<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:416f8203-784d-47d5-afb2-da7e80ab2748,g:90857bc1-b6ae-47e1-b7c5-75c590d1d348-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://hydrafacial.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="skin-20250331.xsd#CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_a3bc3a2f-8300-4c36-bbb9-f27008d9085f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_fb509993-4ef7-4f3e-8021-1c4570d2040a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_a3bc3a2f-8300-4c36-bbb9-f27008d9085f" xlink:to="loc_us-gaap_StatementTable_fb509993-4ef7-4f3e-8021-1c4570d2040a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d1946520-a0f2-4f8c-bb80-f038f836b1ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_fb509993-4ef7-4f3e-8021-1c4570d2040a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d1946520-a0f2-4f8c-bb80-f038f836b1ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d1946520-a0f2-4f8c-bb80-f038f836b1ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d1946520-a0f2-4f8c-bb80-f038f836b1ec" xlink:to="loc_us-gaap_EquityComponentDomain_d1946520-a0f2-4f8c-bb80-f038f836b1ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d1946520-a0f2-4f8c-bb80-f038f836b1ec" xlink:to="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_29bf1395-de94-4992-bc4b-d6e7fa1570a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:to="loc_us-gaap_CommonStockMember_29bf1395-de94-4992-bc4b-d6e7fa1570a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_5548314e-89ee-4d56-8c94-5ae0fc66620e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_5548314e-89ee-4d56-8c94-5ae0fc66620e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e48372dd-22d7-40a2-a956-47d0d888e43c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e48372dd-22d7-40a2-a956-47d0d888e43c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_65fde07e-08ce-470c-9d97-7b95ae20364c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b11bbacb-a9d1-4296-9aef-4c336b2a3773" xlink:to="loc_us-gaap_RetainedEarningsMember_65fde07e-08ce-470c-9d97-7b95ae20364c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_a3bc3a2f-8300-4c36-bbb9-f27008d9085f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_abb16a79-f9c8-4953-ac04-328d995a0b45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_abb16a79-f9c8-4953-ac04-328d995a0b45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_93af022b-0a6a-4349-98c1-9cb8f8a7d0ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_StockholdersEquity_93af022b-0a6a-4349-98c1-9cb8f8a7d0ba" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_537a9fb0-6abf-49a3-b478-d43d2f986c2b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_NetIncomeLoss_537a9fb0-6abf-49a3-b478-d43d2f986c2b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_66e0b54e-91bf-4369-99da-1c3e68d5de6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_66e0b54e-91bf-4369-99da-1c3e68d5de6a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_ae319aff-f0dc-429a-8b56-e96f9b203962" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_ae319aff-f0dc-429a-8b56-e96f9b203962" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_2549551e-dc3b-4eb9-8cb2-9541cf09e701" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_2549551e-dc3b-4eb9-8cb2-9541cf09e701" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_d630e317-3be5-4c8f-8545-3964d3debf69" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_d630e317-3be5-4c8f-8545-3964d3debf69" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_dc0e7bc0-3a7d-4883-95e6-52f84b9a86d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_569a66c1-7981-4e9d-b97c-13a93f50009f" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_dc0e7bc0-3a7d-4883-95e6-52f84b9a86d7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_f182941d-dfa9-4a97-98f4-7e79b15f5d92" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_e21e0cd4-0620-4223-a8f0-c6427db85f93" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/DescriptionofBusinessDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#DescriptionofBusinessDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/DescriptionofBusinessDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_d310d739-477b-438d-bf39-5d9608a28107" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_043c0096-a189-4658-bfea-c8590b1e3e32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d310d739-477b-438d-bf39-5d9608a28107" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_043c0096-a189-4658-bfea-c8590b1e3e32" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_ce79550e-4c7e-495e-a412-70d1784ee1ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_043c0096-a189-4658-bfea-c8590b1e3e32" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_ce79550e-4c7e-495e-a412-70d1784ee1ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ce79550e-4c7e-495e-a412-70d1784ee1ac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ce79550e-4c7e-495e-a412-70d1784ee1ac" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ce79550e-4c7e-495e-a412-70d1784ee1ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cf27d1e3-fa28-42c2-92df-df168e405eaa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ce79550e-4c7e-495e-a412-70d1784ee1ac" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cf27d1e3-fa28-42c2-92df-df168e405eaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_HydrafacialMember_9d0e4cb4-2654-4d01-b055-21e493825607" xlink:href="skin-20250331.xsd#skin_HydrafacialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cf27d1e3-fa28-42c2-92df-df168e405eaa" xlink:to="loc_skin_HydrafacialMember_9d0e4cb4-2654-4d01-b055-21e493825607" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_MergerSubIIMember_230bf002-8068-44b4-a69f-a03784d0dab3" xlink:href="skin-20250331.xsd#skin_MergerSubIIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cf27d1e3-fa28-42c2-92df-df168e405eaa" xlink:to="loc_skin_MergerSubIIMember_230bf002-8068-44b4-a69f-a03784d0dab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_HydrafacialAndSubsidiariesMember_16cbb349-fb03-4926-b027-d8a8bb7de5de" xlink:href="skin-20250331.xsd#skin_HydrafacialAndSubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cf27d1e3-fa28-42c2-92df-df168e405eaa" xlink:to="loc_skin_HydrafacialAndSubsidiariesMember_16cbb349-fb03-4926-b027-d8a8bb7de5de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_c327d6eb-fb54-4cab-a1f0-9c683d9f2d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d310d739-477b-438d-bf39-5d9608a28107" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_c327d6eb-fb54-4cab-a1f0-9c683d9f2d6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_9be010d2-1788-451e-85aa-e24dfcaf8993" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_d310d739-477b-438d-bf39-5d9608a28107" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_9be010d2-1788-451e-85aa-e24dfcaf8993" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/PropertyandEquipmentnetDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#PropertyandEquipmentnetDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/PropertyandEquipmentnetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea114100-596c-42e6-877f-f0263db5774f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea114100-596c-42e6-877f-f0263db5774f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8663e62-46b1-40dd-b5e1-85f345f955fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea114100-596c-42e6-877f-f0263db5774f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8663e62-46b1-40dd-b5e1-85f345f955fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c8663e62-46b1-40dd-b5e1-85f345f955fb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8663e62-46b1-40dd-b5e1-85f345f955fb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c8663e62-46b1-40dd-b5e1-85f345f955fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4d500986-8bea-4835-96e1-8eea8b9df4bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8663e62-46b1-40dd-b5e1-85f345f955fb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4d500986-8bea-4835-96e1-8eea8b9df4bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:href="skin-20250331.xsd#skin_DepreciablePropertyPlantAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4d500986-8bea-4835-96e1-8eea8b9df4bc" xlink:to="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_9d58b960-4796-4f0d-82e6-e701e1682eba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_9d58b960-4796-4f0d-82e6-e701e1682eba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_d014e8c3-687c-4728-88f6-d59518efde72" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_d014e8c3-687c-4728-88f6-d59518efde72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_47b65f29-e46d-47be-874e-6f83cf46619b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_47b65f29-e46d-47be-874e-6f83cf46619b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OfficeEquipmentMember_a972a17f-f919-4546-8c82-d48f3e731972" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OfficeEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_OfficeEquipmentMember_a972a17f-f919-4546-8c82-d48f3e731972" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ToolsDiesAndMoldsMember_863d0a3c-9518-4280-96a9-e108fb3da966" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ToolsDiesAndMoldsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_ToolsDiesAndMoldsMember_863d0a3c-9518-4280-96a9-e108fb3da966" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VehiclesMember_431826e8-7395-49ab-9822-1539592fd0f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_skin_DepreciablePropertyPlantAndEquipmentMember_6b9844a3-5b49-41cc-95a4-513c8b628e32" xlink:to="loc_us-gaap_VehiclesMember_431826e8-7395-49ab-9822-1539592fd0f2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_47dbd0c5-3099-4596-93f0-46fb4726756c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ea114100-596c-42e6-877f-f0263db5774f" xlink:to="loc_srt_RangeAxis_47dbd0c5-3099-4596-93f0-46fb4726756c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_47dbd0c5-3099-4596-93f0-46fb4726756c_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_47dbd0c5-3099-4596-93f0-46fb4726756c" xlink:to="loc_srt_RangeMember_47dbd0c5-3099-4596-93f0-46fb4726756c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_3f9cb7a1-bf15-4850-b2c3-b63bc87fde0b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_47dbd0c5-3099-4596-93f0-46fb4726756c" xlink:to="loc_srt_RangeMember_3f9cb7a1-bf15-4850-b2c3-b63bc87fde0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_b292aedd-74ce-4cc5-8c83-caf822c508d0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3f9cb7a1-bf15-4850-b2c3-b63bc87fde0b" xlink:to="loc_srt_MinimumMember_b292aedd-74ce-4cc5-8c83-caf822c508d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_071690b5-be33-475a-bb9d-8026386de36f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_3f9cb7a1-bf15-4850-b2c3-b63bc87fde0b" xlink:to="loc_srt_MaximumMember_071690b5-be33-475a-bb9d-8026386de36f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_8466e70e-6b59-4e83-8c2c-a70d52f58669" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_8466e70e-6b59-4e83-8c2c-a70d52f58669" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_fa16bdf6-5b02-45d3-b294-f2c1b484fe7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization_fa16bdf6-5b02-45d3-b294-f2c1b484fe7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_525008f6-a217-4dfe-b1b5-7444ca545982" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization_525008f6-a217-4dfe-b1b5-7444ca545982" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_dcb8c5c4-b55f-4dc5-877d-c69ba2c0c099" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_ceb33102-455c-46b1-b6aa-d88601eb895c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_dcb8c5c4-b55f-4dc5-877d-c69ba2c0c099" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/GoodwillandIntangibleAssetsnetIntangibleAssetsDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#GoodwillandIntangibleAssetsnetIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/GoodwillandIntangibleAssetsnetIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6b1df229-f499-4f57-8052-6194f82c8ddf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6b1df229-f499-4f57-8052-6194f82c8ddf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_05688f2f-825e-495b-b469-499d6ba4972f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6b1df229-f499-4f57-8052-6194f82c8ddf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_05688f2f-825e-495b-b469-499d6ba4972f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05688f2f-825e-495b-b469-499d6ba4972f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_05688f2f-825e-495b-b469-499d6ba4972f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_05688f2f-825e-495b-b469-499d6ba4972f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_05688f2f-825e-495b-b469-499d6ba4972f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_fb6d3da9-beb0-45e9-9fbc-e4294f9a7c18" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_fb6d3da9-beb0-45e9-9fbc-e4294f9a7c18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_7d453a32-6db4-4e36-a78f-6d5c1987f412" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_7d453a32-6db4-4e36-a78f-6d5c1987f412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_456ad5e6-c5b8-46d8-a5db-555cec1482c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_CustomerRelationshipsMember_456ad5e6-c5b8-46d8-a5db-555cec1482c3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_bbf9d176-363d-4e6c-be10-775a0db16e17" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_TrademarksMember_bbf9d176-363d-4e6c-be10-775a0db16e17" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncompeteAgreementsMember_bf5f34de-3749-408e-b337-e11dfcb79d09" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncompeteAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_NoncompeteAgreementsMember_bf5f34de-3749-408e-b337-e11dfcb79d09" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PatentsMember_ba5899f9-c28d-4fcc-8520-61ff06f27b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PatentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_ed9bb64d-dcf5-4dc6-87d8-4833f8a04283" xlink:to="loc_us-gaap_PatentsMember_ba5899f9-c28d-4fcc-8520-61ff06f27b4a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_a8609d0f-6e2a-4809-822e-25ce816da768" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_6b1df229-f499-4f57-8052-6194f82c8ddf" xlink:to="loc_srt_RangeAxis_a8609d0f-6e2a-4809-822e-25ce816da768" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_a8609d0f-6e2a-4809-822e-25ce816da768_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_a8609d0f-6e2a-4809-822e-25ce816da768" xlink:to="loc_srt_RangeMember_a8609d0f-6e2a-4809-822e-25ce816da768_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_551296d5-edba-40c2-b96b-3e5013278fda" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_a8609d0f-6e2a-4809-822e-25ce816da768" xlink:to="loc_srt_RangeMember_551296d5-edba-40c2-b96b-3e5013278fda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_70b1cf82-c935-45ea-bf3f-f72c4e967fda" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_551296d5-edba-40c2-b96b-3e5013278fda" xlink:to="loc_srt_MinimumMember_70b1cf82-c935-45ea-bf3f-f72c4e967fda" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_8fe94b85-e2c2-47be-b5f9-7fe31191ff47" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_551296d5-edba-40c2-b96b-3e5013278fda" xlink:to="loc_srt_MaximumMember_8fe94b85-e2c2-47be-b5f9-7fe31191ff47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_a1d57ea3-dc85-42d4-908f-81e54f09bfde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_a1d57ea3-dc85-42d4-908f-81e54f09bfde" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_2990ed9f-39b7-4324-9588-6f9b098ae2a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_2990ed9f-39b7-4324-9588-6f9b098ae2a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_0af812c6-d846-4d8f-b97b-f11eba38fac4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_0af812c6-d846-4d8f-b97b-f11eba38fac4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_ed03ee2b-6ff8-4a2f-9383-c2b853514800" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b59f4797-8d6b-4e9f-988f-9a19d3348361" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_ed03ee2b-6ff8-4a2f-9383-c2b853514800" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/LongtermDebtNarrativeDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#LongtermDebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/LongtermDebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_02fa0e2c-c9dd-441b-b23a-06cbaac2e99c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_DebtInstrumentTable_02fa0e2c-c9dd-441b-b23a-06cbaac2e99c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_5ca608ae-6248-476a-b3ae-d795f23d957c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02fa0e2c-c9dd-441b-b23a-06cbaac2e99c" xlink:to="loc_us-gaap_DebtInstrumentAxis_5ca608ae-6248-476a-b3ae-d795f23d957c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_5ca608ae-6248-476a-b3ae-d795f23d957c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_5ca608ae-6248-476a-b3ae-d795f23d957c" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_5ca608ae-6248-476a-b3ae-d795f23d957c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_066f600b-527f-4545-b7a7-14d2aef5abb8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_5ca608ae-6248-476a-b3ae-d795f23d957c" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_066f600b-527f-4545-b7a7-14d2aef5abb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_A125ConvertibleSeniorNotesDue2026Member_bbcbb478-f9ed-4034-b65e-9e385753aa16" xlink:href="skin-20250331.xsd#skin_A125ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_066f600b-527f-4545-b7a7-14d2aef5abb8" xlink:to="loc_skin_A125ConvertibleSeniorNotesDue2026Member_bbcbb478-f9ed-4034-b65e-9e385753aa16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02fa0e2c-c9dd-441b-b23a-06cbaac2e99c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_0bb7883b-1949-418b-89f0-6fdde32eabbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3fd3f7ae-e187-4cbc-8363-fd7d1285e21c" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_0bb7883b-1949-418b-89f0-6fdde32eabbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_6359a664-6ede-4d8c-a08d-1cd5a9f31fe0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_0bb7883b-1949-418b-89f0-6fdde32eabbc" xlink:to="loc_us-gaap_ConvertibleDebtMember_6359a664-6ede-4d8c-a08d-1cd5a9f31fe0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a6df44c4-93b4-4f44-93f4-82c5914a1476" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02fa0e2c-c9dd-441b-b23a-06cbaac2e99c" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a6df44c4-93b4-4f44-93f4-82c5914a1476" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a6df44c4-93b4-4f44-93f4-82c5914a1476_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a6df44c4-93b4-4f44-93f4-82c5914a1476" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a6df44c4-93b4-4f44-93f4-82c5914a1476_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9aa5876b-cceb-40d7-9d0d-4572a1b9b81f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a6df44c4-93b4-4f44-93f4-82c5914a1476" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9aa5876b-cceb-40d7-9d0d-4572a1b9b81f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_6dc5b54b-1d42-4b95-a02f-fd8bd1274aaf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9aa5876b-cceb-40d7-9d0d-4572a1b9b81f" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_6dc5b54b-1d42-4b95-a02f-fd8bd1274aaf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_54fa47bc-64a0-4a6f-979a-1b27cde15f41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_54fa47bc-64a0-4a6f-979a-1b27cde15f41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_ff248045-40fb-4969-bd95-8e99a2729799" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_ff248045-40fb-4969-bd95-8e99a2729799" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_DebtInstrumentAccordionFeatureSettlementPeriod_ac46a11e-27cc-4f24-9ea1-f06989d99461" xlink:href="skin-20250331.xsd#skin_DebtInstrumentAccordionFeatureSettlementPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_skin_DebtInstrumentAccordionFeatureSettlementPeriod_ac46a11e-27cc-4f24-9ea1-f06989d99461" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_DebtInstrumentAccordionFeatureIncreaseLimit_55f85af8-98f2-441f-820d-5967dac82818" xlink:href="skin-20250331.xsd#skin_DebtInstrumentAccordionFeatureIncreaseLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_skin_DebtInstrumentAccordionFeatureIncreaseLimit_55f85af8-98f2-441f-820d-5967dac82818" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_969ac1df-db25-4c2b-a80c-10e7cc7a3909" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRepurchasedFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_DebtInstrumentRepurchasedFaceAmount_969ac1df-db25-4c2b-a80c-10e7cc7a3909" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfConvertibleDebt_d3165c36-c2f5-4319-8078-4328adff7846" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfConvertibleDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_RepaymentsOfConvertibleDebt_d3165c36-c2f5-4319-8078-4328adff7846" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_af1a2eaa-45c7-4b2c-bc0f-3800b1ec679d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_af1a2eaa-45c7-4b2c-bc0f-3800b1ec679d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtFairValueDisclosures_0c62c59d-6a91-4ad4-b53f-d3237f343777" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleDebtFairValueDisclosures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e9030c19-31d8-4698-89fd-c20b89a6b62e" xlink:to="loc_us-gaap_ConvertibleDebtFairValueDisclosures_0c62c59d-6a91-4ad4-b53f-d3237f343777" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/LongTermDebtScheduleofLongtermDebtDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#LongTermDebtScheduleofLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/LongTermDebtScheduleofLongtermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9ab70c4b-be57-4e24-adf6-8ae3d01fb7ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_a1957b2f-191d-4d16-90b7-64d846355454" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ab70c4b-be57-4e24-adf6-8ae3d01fb7ae" xlink:to="loc_us-gaap_DebtInstrumentTable_a1957b2f-191d-4d16-90b7-64d846355454" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_5ed5ada4-bcc9-405a-83a4-502502cc00f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_a1957b2f-191d-4d16-90b7-64d846355454" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_5ed5ada4-bcc9-405a-83a4-502502cc00f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5ed5ada4-bcc9-405a-83a4-502502cc00f5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5ed5ada4-bcc9-405a-83a4-502502cc00f5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5ed5ada4-bcc9-405a-83a4-502502cc00f5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e8652670-808e-439f-8754-37a080536332" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_5ed5ada4-bcc9-405a-83a4-502502cc00f5" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e8652670-808e-439f-8754-37a080536332" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtMember_7b299711-0bbd-4aba-ac65-612a6ee6ff6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_e8652670-808e-439f-8754-37a080536332" xlink:to="loc_us-gaap_ConvertibleDebtMember_7b299711-0bbd-4aba-ac65-612a6ee6ff6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_4aacebe6-0c8a-4307-babb-74e0f06e4269" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_a1957b2f-191d-4d16-90b7-64d846355454" xlink:to="loc_us-gaap_DebtInstrumentAxis_4aacebe6-0c8a-4307-babb-74e0f06e4269" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4aacebe6-0c8a-4307-babb-74e0f06e4269_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_4aacebe6-0c8a-4307-babb-74e0f06e4269" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4aacebe6-0c8a-4307-babb-74e0f06e4269_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_46a2607c-bd4d-4f44-98a2-3428b62ea3fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_4aacebe6-0c8a-4307-babb-74e0f06e4269" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_46a2607c-bd4d-4f44-98a2-3428b62ea3fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_A125ConvertibleSeniorNotesDue2026Member_e9de30d9-ecc8-41ba-bf12-45b74da4a09d" xlink:href="skin-20250331.xsd#skin_A125ConvertibleSeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_46a2607c-bd4d-4f44-98a2-3428b62ea3fc" xlink:to="loc_skin_A125ConvertibleSeniorNotesDue2026Member_e9de30d9-ecc8-41ba-bf12-45b74da4a09d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_a3be6d66-b4fb-4a1d-858b-078334e4a777" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ab70c4b-be57-4e24-adf6-8ae3d01fb7ae" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_a3be6d66-b4fb-4a1d-858b-078334e4a777" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_d600897c-09fd-4540-8ef9-cde202a5c225" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ab70c4b-be57-4e24-adf6-8ae3d01fb7ae" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_d600897c-09fd-4540-8ef9-cde202a5c225" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_96ee45e1-656c-4473-a54d-564dd0642310" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9ab70c4b-be57-4e24-adf6-8ae3d01fb7ae" xlink:to="loc_us-gaap_LongTermDebt_96ee45e1-656c-4473-a54d-564dd0642310" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_5dc7c42c-d891-42e3-a475-584ce444e148" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_us-gaap_LossContingenciesTable_5dc7c42c-d891-42e3-a475-584ce444e148" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_5dc7c42c-d891-42e3-a475-584ce444e148" xlink:to="loc_srt_LitigationCaseAxis_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3" xlink:to="loc_srt_LitigationCaseTypeDomain_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_4ed5d1a9-26fd-4ea4-9ac9-da73a8934dc3" xlink:to="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_EdgeSystemsLLCVCartessaAestheticsLLCMember_4a299bb5-d537-4e3b-8192-d0826f8bc839" xlink:href="skin-20250331.xsd#skin_EdgeSystemsLLCVCartessaAestheticsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_EdgeSystemsLLCVCartessaAestheticsLLCMember_4a299bb5-d537-4e3b-8192-d0826f8bc839" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_SecuritiesClassActionMember_88c362c3-fba0-4e2f-bbc1-64540deb8002" xlink:href="skin-20250331.xsd#skin_SecuritiesClassActionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_SecuritiesClassActionMember_88c362c3-fba0-4e2f-bbc1-64540deb8002" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_LuvoMedicalTechnologiesIncMember_ee2ef4f0-4e82-4fb3-8b51-e107fd4ff74d" xlink:href="skin-20250331.xsd#skin_LuvoMedicalTechnologiesIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_LuvoMedicalTechnologiesIncMember_ee2ef4f0-4e82-4fb3-8b51-e107fd4ff74d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_AestheticManagementPartnersInc.Member_9a181e0a-d6f6-4570-9fc9-8a65a1addfde" xlink:href="skin-20250331.xsd#skin_AestheticManagementPartnersInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_AestheticManagementPartnersInc.Member_9a181e0a-d6f6-4570-9fc9-8a65a1addfde" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_EMIRAmedUSALLCMember_123f6828-4ec6-451b-ad50-38d3fe2a3467" xlink:href="skin-20250331.xsd#skin_EMIRAmedUSALLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_EMIRAmedUSALLCMember_123f6828-4ec6-451b-ad50-38d3fe2a3467" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_SinclairPharmaUSIncMember_1554fe58-fec8-4db6-94ef-0356551b768f" xlink:href="skin-20250331.xsd#skin_SinclairPharmaUSIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_SinclairPharmaUSIncMember_1554fe58-fec8-4db6-94ef-0356551b768f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_MedicreationsLLCMember_2b261f72-3b79-4add-8673-629e312034b3" xlink:href="skin-20250331.xsd#skin_MedicreationsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_MedicreationsLLCMember_2b261f72-3b79-4add-8673-629e312034b3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_CandelaCorp.Member_f19f7637-68ad-46c6-9782-8ab3ecbd8e85" xlink:href="skin-20250331.xsd#skin_CandelaCorp.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_CandelaCorp.Member_f19f7637-68ad-46c6-9782-8ab3ecbd8e85" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_MedicalPurchasingResourceLLCMember_dee52a79-0d66-4673-8dfb-9ae8be743789" xlink:href="skin-20250331.xsd#skin_MedicalPurchasingResourceLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_92ec6a01-8c2b-4fa7-8481-3bf94ac7f794" xlink:to="loc_skin_MedicalPurchasingResourceLLCMember_dee52a79-0d66-4673-8dfb-9ae8be743789" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_759ff01c-47a5-41c9-9320-5d2238fb3027" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_5dc7c42c-d891-42e3-a475-584ce444e148" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_759ff01c-47a5-41c9-9320-5d2238fb3027" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_759ff01c-47a5-41c9-9320-5d2238fb3027_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_759ff01c-47a5-41c9-9320-5d2238fb3027" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_759ff01c-47a5-41c9-9320-5d2238fb3027_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_f13a6d15-5ad5-4057-968d-5d97bf973c9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_759ff01c-47a5-41c9-9320-5d2238fb3027" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_f13a6d15-5ad5-4057-968d-5d97bf973c9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_a42ef354-00d4-49f7-b782-b06cbe4de162" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_f13a6d15-5ad5-4057-968d-5d97bf973c9f" xlink:to="loc_us-gaap_SubsequentEventMember_a42ef354-00d4-49f7-b782-b06cbe4de162" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_83a65ecf-4cce-492a-9199-af146aa6e5eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_5dc7c42c-d891-42e3-a475-584ce444e148" xlink:to="loc_us-gaap_LitigationStatusAxis_83a65ecf-4cce-492a-9199-af146aa6e5eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_83a65ecf-4cce-492a-9199-af146aa6e5eb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_83a65ecf-4cce-492a-9199-af146aa6e5eb" xlink:to="loc_us-gaap_LitigationStatusDomain_83a65ecf-4cce-492a-9199-af146aa6e5eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_2c12ef0b-38bd-452a-bcb3-41d15e4f0cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_83a65ecf-4cce-492a-9199-af146aa6e5eb" xlink:to="loc_us-gaap_LitigationStatusDomain_2c12ef0b-38bd-452a-bcb3-41d15e4f0cb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_0cbaa2b3-6534-4002-b5d5-ddb6938f3732" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_2c12ef0b-38bd-452a-bcb3-41d15e4f0cb2" xlink:to="loc_us-gaap_PendingLitigationMember_0cbaa2b3-6534-4002-b5d5-ddb6938f3732" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingencyPatentsAllegedlyInfringedUponNumber_c6fff83d-338f-4d73-ade7-63c1e4a04ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainContingencyPatentsAllegedlyInfringedUponNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_us-gaap_GainContingencyPatentsAllegedlyInfringedUponNumber_c6fff83d-338f-4d73-ade7-63c1e4a04ff2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_GainContingencyPatentsAllegedlyInfringedNumberRevised_4227fb0d-709a-4582-b260-ce73a1b46402" xlink:href="skin-20250331.xsd#skin_GainContingencyPatentsAllegedlyInfringedNumberRevised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_GainContingencyPatentsAllegedlyInfringedNumberRevised_4227fb0d-709a-4582-b260-ce73a1b46402" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_GainContingencyPatentsAllegedlyInfringedPartialDenialOfMotionForSummaryJudgementOfNonInfringementNumber_26c6143a-c52d-4268-8fbd-b72228987c7c" xlink:href="skin-20250331.xsd#skin_GainContingencyPatentsAllegedlyInfringedPartialDenialOfMotionForSummaryJudgementOfNonInfringementNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_GainContingencyPatentsAllegedlyInfringedPartialDenialOfMotionForSummaryJudgementOfNonInfringementNumber_26c6143a-c52d-4268-8fbd-b72228987c7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedFromOtherParty_d5eeaba4-06e0-42c1-80e4-08bf7c8d807c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationSettlementAmountAwardedFromOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedFromOtherParty_d5eeaba4-06e0-42c1-80e4-08bf7c8d807c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_LitigationSettlementAmountAwardedNumberOfPaymentsToBeReceived_0943722e-b687-4d16-bf97-8508c9a03b0d" xlink:href="skin-20250331.xsd#skin_LitigationSettlementAmountAwardedNumberOfPaymentsToBeReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_LitigationSettlementAmountAwardedNumberOfPaymentsToBeReceived_0943722e-b687-4d16-bf97-8508c9a03b0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_LitigationSettlementAmountAwardedIndividualPaymentAmount_940177c9-4186-44cc-a2d7-61d76971cbec" xlink:href="skin-20250331.xsd#skin_LitigationSettlementAmountAwardedIndividualPaymentAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_LitigationSettlementAmountAwardedIndividualPaymentAmount_940177c9-4186-44cc-a2d7-61d76971cbec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_LossContingencyNumberOfCompetingMotions_5189972f-ca0b-44c9-af38-405289f36869" xlink:href="skin-20250331.xsd#skin_LossContingencyNumberOfCompetingMotions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_LossContingencyNumberOfCompetingMotions_5189972f-ca0b-44c9-af38-405289f36869" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_NumberOfSubpoenasIssuedBySEC_9fe7a282-8aad-4c8c-bfdf-bea10b3d9a58" xlink:href="skin-20250331.xsd#skin_NumberOfSubpoenasIssuedBySEC"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_c3f63d6f-69f7-44e7-ad88-8827b601a5c6" xlink:to="loc_skin_NumberOfSubpoenasIssuedBySEC_9fe7a282-8aad-4c8c-bfdf-bea10b3d9a58" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/RelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#RelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ad7c1b73-d048-4fe1-9578-4362255d7816" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ad7c1b73-d048-4fe1-9578-4362255d7816" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4e15186f-65c0-4c8a-b318-1446fb93c53c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ad7c1b73-d048-4fe1-9578-4362255d7816" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4e15186f-65c0-4c8a-b318-1446fb93c53c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_4e15186f-65c0-4c8a-b318-1446fb93c53c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4e15186f-65c0-4c8a-b318-1446fb93c53c" xlink:to="loc_us-gaap_RelatedPartyDomain_4e15186f-65c0-4c8a-b318-1446fb93c53c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_c6d81073-4adb-47c8-9191-06a0802e08e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_4e15186f-65c0-4c8a-b318-1446fb93c53c" xlink:to="loc_us-gaap_RelatedPartyDomain_c6d81073-4adb-47c8-9191-06a0802e08e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_2099cbbd-80f8-4452-8233-2fa7d3df2e93" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_c6d81073-4adb-47c8-9191-06a0802e08e0" xlink:to="loc_us-gaap_RelatedPartyMember_2099cbbd-80f8-4452-8233-2fa7d3df2e93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_7f828f93-5da9-4cf7-bcdd-d4421be25d9d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ad7c1b73-d048-4fe1-9578-4362255d7816" xlink:to="loc_srt_CounterpartyNameAxis_7f828f93-5da9-4cf7-bcdd-d4421be25d9d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7f828f93-5da9-4cf7-bcdd-d4421be25d9d_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_7f828f93-5da9-4cf7-bcdd-d4421be25d9d" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7f828f93-5da9-4cf7-bcdd-d4421be25d9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_622da6f8-ae1a-43fa-9ebe-308f155f7bb2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_7f828f93-5da9-4cf7-bcdd-d4421be25d9d" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_622da6f8-ae1a-43fa-9ebe-308f155f7bb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_VesperFoundersMember_9ffa614f-6ad5-4456-be9d-f0bc46635c45" xlink:href="skin-20250331.xsd#skin_VesperFoundersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_622da6f8-ae1a-43fa-9ebe-308f155f7bb2" xlink:to="loc_skin_VesperFoundersMember_9ffa614f-6ad5-4456-be9d-f0bc46635c45" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_LCPEdgeHoldcoLLCMember_1f3e7dac-f853-41a6-a034-46f83e95622e" xlink:href="skin-20250331.xsd#skin_LCPEdgeHoldcoLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_622da6f8-ae1a-43fa-9ebe-308f155f7bb2" xlink:to="loc_skin_LCPEdgeHoldcoLLCMember_1f3e7dac-f853-41a6-a034-46f83e95622e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ad7c1b73-d048-4fe1-9578-4362255d7816" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_dc4932c0-0eef-4363-9624-006ff4f36484" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_c61455f4-ba3b-40c8-9ce2-86a1a9cb1c0b" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_dc4932c0-0eef-4363-9624-006ff4f36484" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_PrivatePlacementWarrantsMember_6f2f494d-c267-4abf-a3aa-49ab1a0b5284" xlink:href="skin-20250331.xsd#skin_PrivatePlacementWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_dc4932c0-0eef-4363-9624-006ff4f36484" xlink:to="loc_skin_PrivatePlacementWarrantsMember_6f2f494d-c267-4abf-a3aa-49ab1a0b5284" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_c86eea80-c246-4b57-bda5-bdd06586414c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_c86eea80-c246-4b57-bda5-bdd06586414c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_TheRegistrationRightsAgreementFilingTimeline_c846f418-edd4-4070-9099-4d1744141f9e" xlink:href="skin-20250331.xsd#skin_TheRegistrationRightsAgreementFilingTimeline"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_TheRegistrationRightsAgreementFilingTimeline_c846f418-edd4-4070-9099-4d1744141f9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_TheRegistrationRightsAgreementNumberOfDemandsForRegistrationAllowed_eacd9869-a7de-466f-a9e0-d1c94f23cdd0" xlink:href="skin-20250331.xsd#skin_TheRegistrationRightsAgreementNumberOfDemandsForRegistrationAllowed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_TheRegistrationRightsAgreementNumberOfDemandsForRegistrationAllowed_eacd9869-a7de-466f-a9e0-d1c94f23cdd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriod_dcdf4218-e115-41e9-a2c3-5703037d4286" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriod_dcdf4218-e115-41e9-a2c3-5703037d4286" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodStockPriceTrigger_568e06ff-9fe1-430b-8b68-20a7323600b1" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodStockPriceTrigger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodStockPriceTrigger_568e06ff-9fe1-430b-8b68-20a7323600b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdBusinessDays_30c83ace-fc20-45ac-b0be-b8cc7ddba817" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdBusinessDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdBusinessDays_30c83ace-fc20-45ac-b0be-b8cc7ddba817" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdConsecutiveTradingDays_c327d9eb-5889-4cec-a15b-d00ca66d82cb" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdConsecutiveTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationContingentConsiderationEquityEarnoutPeriodThresholdConsecutiveTradingDays_c327d9eb-5889-4cec-a15b-d00ca66d82cb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationContingentConsiderationEquityCommencementPeriod_dc88e90c-41e1-46fe-814c-023c417d5d1d" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationContingentConsiderationEquityCommencementPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationContingentConsiderationEquityCommencementPeriod_dc88e90c-41e1-46fe-814c-023c417d5d1d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdOneDirector_c90e09dc-b726-45a4-a1c1-12f4901238f2" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdOneDirector"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdOneDirector_c90e09dc-b726-45a4-a1c1-12f4901238f2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdTwoDirectors_0531df6c-6d1c-441f-ac3f-ff4d15f57d1e" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdTwoDirectors"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdTwoDirectors_0531df6c-6d1c-441f-ac3f-ff4d15f57d1e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdThreeDirectors_4eb761df-cba4-4229-a2b5-9a07a63dbba8" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdThreeDirectors"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationRightToDesignateDirectorsPercentageThresholdThreeDirectors_4eb761df-cba4-4229-a2b5-9a07a63dbba8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ReverseRecapitalizationRightToDesignateOneDirectorOnBoardPercentageThreshold_b0de3bf7-9c17-437f-96a9-d8460bf01b10" xlink:href="skin-20250331.xsd#skin_ReverseRecapitalizationRightToDesignateOneDirectorOnBoardPercentageThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_d18e733b-f2f9-4e1c-b601-3e0e1e994b41" xlink:to="loc_skin_ReverseRecapitalizationRightToDesignateOneDirectorOnBoardPercentageThreshold_b0de3bf7-9c17-437f-96a9-d8460bf01b10" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/StockholdersEquityDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#StockholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/StockholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_d674cdcd-e166-4516-ada9-d86fb54e998e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_d674cdcd-e166-4516-ada9-d86fb54e998e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_7d80ac1f-c6cb-4f01-a134-626e97294ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_d674cdcd-e166-4516-ada9-d86fb54e998e" xlink:to="loc_us-gaap_StatementClassOfStockAxis_7d80ac1f-c6cb-4f01-a134-626e97294ca3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_7d80ac1f-c6cb-4f01-a134-626e97294ca3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7d80ac1f-c6cb-4f01-a134-626e97294ca3" xlink:to="loc_us-gaap_ClassOfStockDomain_7d80ac1f-c6cb-4f01-a134-626e97294ca3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a179de10-e78a-4101-a2e1-1fdbc62ffd97" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7d80ac1f-c6cb-4f01-a134-626e97294ca3" xlink:to="loc_us-gaap_ClassOfStockDomain_a179de10-e78a-4101-a2e1-1fdbc62ffd97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_9115dcaa-289f-4e3f-b5cb-0d4683e34110" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_a179de10-e78a-4101-a2e1-1fdbc62ffd97" xlink:to="loc_us-gaap_CommonClassAMember_9115dcaa-289f-4e3f-b5cb-0d4683e34110" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_4ad7e56d-e832-455e-9361-222273442709" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_4ad7e56d-e832-455e-9361-222273442709" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_96df87d0-326b-4ced-a897-87fc4e140e18" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_96df87d0-326b-4ced-a897-87fc4e140e18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_CommonStockVotingRightsVotes_79195b4e-f4a1-4a46-bd0a-774e5fe1ee2c" xlink:href="skin-20250331.xsd#skin_CommonStockVotingRightsVotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_skin_CommonStockVotingRightsVotes_79195b4e-f4a1-4a46-bd0a-774e5fe1ee2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_cf709d85-c9f2-4605-a288-33585f7e1068" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_cf709d85-c9f2-4605-a288-33585f7e1068" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_ce1dab8c-bc77-46b1-a87e-5d58ee3f7d44" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_ce1dab8c-bc77-46b1-a87e-5d58ee3f7d44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_f709c620-5719-4fb7-b03a-f0f18f5b3e14" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_f709c620-5719-4fb7-b03a-f0f18f5b3e14" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_4d825e12-1227-4642-ad5c-0fe83822c663" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_4d825e12-1227-4642-ad5c-0fe83822c663" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_218c9698-9625-48fa-b2ba-66e536db185a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_218c9698-9625-48fa-b2ba-66e536db185a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_440b8e9c-683a-4284-8b5f-01fc5a42c5e4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_440b8e9c-683a-4284-8b5f-01fc5a42c5e4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_53a84993-f62e-4808-a6d2-c9eb16717ad1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_PreferredStockSharesIssued_53a84993-f62e-4808-a6d2-c9eb16717ad1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_06a305b6-2440-4461-905f-b2b36495108e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_19b5adb3-5159-4470-80ed-972607b78484" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_06a305b6-2440-4461-905f-b2b36495108e" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/FairValueMeasurementsScheduleofassetsandliabilitiesmeasuredatfairvalueonrecurringbasisDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#FairValueMeasurementsScheduleofassetsandliabilitiesmeasuredatfairvalueonrecurringbasisDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/FairValueMeasurementsScheduleofassetsandliabilitiesmeasuredatfairvalueonrecurringbasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5747c9c1-c0bc-41c5-bdb3-8ec6778cedb4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5747c9c1-c0bc-41c5-bdb3-8ec6778cedb4" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_05da4fdd-0495-499a-8f86-dc9deac531db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_0e003bdf-7ab0-45a6-8bd9-4be61f9510cb" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_05da4fdd-0495-499a-8f86-dc9deac531db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_1482c53d-0235-4db2-91bf-f06ec3419ec1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_05da4fdd-0495-499a-8f86-dc9deac531db" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_1482c53d-0235-4db2-91bf-f06ec3419ec1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cdd8f172-2dea-4a89-83dd-2e944520d45f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cdd8f172-2dea-4a89-83dd-2e944520d45f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_cdd8f172-2dea-4a89-83dd-2e944520d45f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cdd8f172-2dea-4a89-83dd-2e944520d45f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_cdd8f172-2dea-4a89-83dd-2e944520d45f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_23cc1c17-6955-4107-992e-bf29c1fe57f8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cdd8f172-2dea-4a89-83dd-2e944520d45f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_23cc1c17-6955-4107-992e-bf29c1fe57f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_1dda93f4-57c1-4d12-a0c3-25d81f652d9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_23cc1c17-6955-4107-992e-bf29c1fe57f8" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_1dda93f4-57c1-4d12-a0c3-25d81f652d9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_3c40163c-171d-400f-8b7f-b398f85d6245" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_23cc1c17-6955-4107-992e-bf29c1fe57f8" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_3c40163c-171d-400f-8b7f-b398f85d6245" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_5459a7b8-df5d-455d-8a76-41fe9155ae0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_23cc1c17-6955-4107-992e-bf29c1fe57f8" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_5459a7b8-df5d-455d-8a76-41fe9155ae0c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_4673e72d-39d5-4b45-a6f0-18fa70b13500" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_4673e72d-39d5-4b45-a6f0-18fa70b13500" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_4673e72d-39d5-4b45-a6f0-18fa70b13500_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_4673e72d-39d5-4b45-a6f0-18fa70b13500" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_4673e72d-39d5-4b45-a6f0-18fa70b13500_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_1c0758d7-41d8-41eb-a321-0b002620c275" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_4673e72d-39d5-4b45-a6f0-18fa70b13500" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_1c0758d7-41d8-41eb-a321-0b002620c275" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_1354c596-8250-42cc-b690-18fb98af4583" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_1c0758d7-41d8-41eb-a321-0b002620c275" xlink:to="loc_us-gaap_MoneyMarketFundsMember_1354c596-8250-42cc-b690-18fb98af4583" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_b3329408-f6e7-4121-b323-98e1532b18ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eec0af36-5c95-4abf-951f-8f64fe63d827" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_b3329408-f6e7-4121-b323-98e1532b18ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_b3329408-f6e7-4121-b323-98e1532b18ba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_b3329408-f6e7-4121-b323-98e1532b18ba" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_b3329408-f6e7-4121-b323-98e1532b18ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_47ba6e0b-9b70-487d-b089-4e027c4fa39e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_b3329408-f6e7-4121-b323-98e1532b18ba" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_47ba6e0b-9b70-487d-b089-4e027c4fa39e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_PrivatePlacementWarrantsMember_38c8811a-5f75-4cee-89ab-2da31f41d8e8" xlink:href="skin-20250331.xsd#skin_PrivatePlacementWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_47ba6e0b-9b70-487d-b089-4e027c4fa39e" xlink:to="loc_skin_PrivatePlacementWarrantsMember_38c8811a-5f75-4cee-89ab-2da31f41d8e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_e1a97708-6c40-4770-ba58-0d14ae24545c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5747c9c1-c0bc-41c5-bdb3-8ec6778cedb4" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_e1a97708-6c40-4770-ba58-0d14ae24545c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_9b11cd0b-3c0a-4dad-87b0-237d896c76ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_e1a97708-6c40-4770-ba58-0d14ae24545c" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_9b11cd0b-3c0a-4dad-87b0-237d896c76ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_30f411e6-a266-4caa-a865-2a574d356ffa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5747c9c1-c0bc-41c5-bdb3-8ec6778cedb4" xlink:to="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_30f411e6-a266-4caa-a865-2a574d356ffa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_6bcdecf5-3695-481f-a362-e3c945b7616f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialLiabilitiesFairValueDisclosureAbstract_30f411e6-a266-4caa-a865-2a574d356ffa" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_6bcdecf5-3695-481f-a362-e3c945b7616f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#FairValueMeasurementsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/FairValueMeasurementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3d6794a0-16b8-48e0-9d96-cbef5577bfa7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_cc089f3b-3390-4848-9731-9b4fd574af55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3d6794a0-16b8-48e0-9d96-cbef5577bfa7" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_cc089f3b-3390-4848-9731-9b4fd574af55" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightAxis_db432289-c19f-4893-bdda-5e32b8f48496" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_cc089f3b-3390-4848-9731-9b4fd574af55" xlink:to="loc_us-gaap_ClassOfWarrantOrRightAxis_db432289-c19f-4893-bdda-5e32b8f48496" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_db432289-c19f-4893-bdda-5e32b8f48496_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_db432289-c19f-4893-bdda-5e32b8f48496" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_db432289-c19f-4893-bdda-5e32b8f48496_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightDomain_46bfa74e-c96d-4fbd-bf70-98ebfb3d3098" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ClassOfWarrantOrRightAxis_db432289-c19f-4893-bdda-5e32b8f48496" xlink:to="loc_us-gaap_ClassOfWarrantOrRightDomain_46bfa74e-c96d-4fbd-bf70-98ebfb3d3098" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_PrivatePlacementWarrantsMember_3a387563-72d4-4dde-abcd-17867dbca511" xlink:href="skin-20250331.xsd#skin_PrivatePlacementWarrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfWarrantOrRightDomain_46bfa74e-c96d-4fbd-bf70-98ebfb3d3098" xlink:to="loc_skin_PrivatePlacementWarrantsMember_3a387563-72d4-4dde-abcd-17867dbca511" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightOutstanding_3316092c-6e3b-4853-bcf6-752f0921fd5b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3d6794a0-16b8-48e0-9d96-cbef5577bfa7" xlink:to="loc_us-gaap_ClassOfWarrantOrRightOutstanding_3316092c-6e3b-4853-bcf6-752f0921fd5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_e38fd750-373f-4952-83dc-4c7ddc849624" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3d6794a0-16b8-48e0-9d96-cbef5577bfa7" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_e38fd750-373f-4952-83dc-4c7ddc849624" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ClassOfWarrantOrRightExpirationPeriod_1423edb6-b959-4a61-98dd-7c01f59918cf" xlink:href="skin-20250331.xsd#skin_ClassOfWarrantOrRightExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3d6794a0-16b8-48e0-9d96-cbef5577bfa7" xlink:to="loc_skin_ClassOfWarrantOrRightExpirationPeriod_1423edb6-b959-4a61-98dd-7c01f59918cf" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/RevenueRevenueDisaggregatedDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#RevenueRevenueDisaggregatedDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/RevenueRevenueDisaggregatedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_889f3f56-f8c8-4a0b-8a67-4ccb20e70431" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_e0f7cc73-2a08-45f0-99e8-baefc2870b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_889f3f56-f8c8-4a0b-8a67-4ccb20e70431" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_e0f7cc73-2a08-45f0-99e8-baefc2870b1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_487b463d-bf43-4741-8f25-408cc94895f4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_e0f7cc73-2a08-45f0-99e8-baefc2870b1e" xlink:to="loc_srt_ProductOrServiceAxis_487b463d-bf43-4741-8f25-408cc94895f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_487b463d-bf43-4741-8f25-408cc94895f4_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_487b463d-bf43-4741-8f25-408cc94895f4" xlink:to="loc_srt_ProductsAndServicesDomain_487b463d-bf43-4741-8f25-408cc94895f4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_b9705625-1807-481d-a16c-57a3be172d14" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_487b463d-bf43-4741-8f25-408cc94895f4" xlink:to="loc_srt_ProductsAndServicesDomain_b9705625-1807-481d-a16c-57a3be172d14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_DeliverySystemsMember_4ef22ce1-96c7-416c-894c-44371be5dee4" xlink:href="skin-20250331.xsd#skin_DeliverySystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b9705625-1807-481d-a16c-57a3be172d14" xlink:to="loc_skin_DeliverySystemsMember_4ef22ce1-96c7-416c-894c-44371be5dee4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_ConsumablesMember_a2686328-af6a-46a2-8bdd-3bb836971d02" xlink:href="skin-20250331.xsd#skin_ConsumablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_b9705625-1807-481d-a16c-57a3be172d14" xlink:to="loc_skin_ConsumablesMember_a2686328-af6a-46a2-8bdd-3bb836971d02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_11c96a1e-04be-4cf6-8422-d5b86e58f0eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_889f3f56-f8c8-4a0b-8a67-4ccb20e70431" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_11c96a1e-04be-4cf6-8422-d5b86e58f0eb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/RevenueGeographicRegionDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#RevenueGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/RevenueGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_97f0488f-d2b6-42bf-a8f6-c44905fccf40" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_eaa8c030-03dd-41ad-90fb-e37355f653e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_97f0488f-d2b6-42bf-a8f6-c44905fccf40" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_eaa8c030-03dd-41ad-90fb-e37355f653e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_ea684b63-98ae-4be0-820b-781b7e79a3b7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_eaa8c030-03dd-41ad-90fb-e37355f653e9" xlink:to="loc_srt_StatementGeographicalAxis_ea684b63-98ae-4be0-820b-781b7e79a3b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_ea684b63-98ae-4be0-820b-781b7e79a3b7_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_ea684b63-98ae-4be0-820b-781b7e79a3b7" xlink:to="loc_srt_SegmentGeographicalDomain_ea684b63-98ae-4be0-820b-781b7e79a3b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_d87a9309-d7f7-46e4-92a4-5cbb6b1e43f9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_ea684b63-98ae-4be0-820b-781b7e79a3b7" xlink:to="loc_srt_SegmentGeographicalDomain_d87a9309-d7f7-46e4-92a4-5cbb6b1e43f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_4aa41b48-daf3-4a97-a32e-eb934bbdd5a7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d87a9309-d7f7-46e4-92a4-5cbb6b1e43f9" xlink:to="loc_srt_AmericasMember_4aa41b48-daf3-4a97-a32e-eb934bbdd5a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_60d77dc7-e4ad-4cdf-898b-210c9d39888c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d87a9309-d7f7-46e4-92a4-5cbb6b1e43f9" xlink:to="loc_srt_AsiaPacificMember_60d77dc7-e4ad-4cdf-898b-210c9d39888c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_b0633567-f948-4181-875f-2495c5d0e8f0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d87a9309-d7f7-46e4-92a4-5cbb6b1e43f9" xlink:to="loc_us-gaap_EMEAMember_b0633567-f948-4181-875f-2495c5d0e8f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_027f5a32-7498-480d-836c-c0323dfa5d29" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_97f0488f-d2b6-42bf-a8f6-c44905fccf40" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_027f5a32-7498-480d-836c-c0323dfa5d29" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/ShareBasedCompensationScheduleofsharebasedcompensationDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#ShareBasedCompensationScheduleofsharebasedcompensationDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/ShareBasedCompensationScheduleofsharebasedcompensationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_5cc538cb-b54e-4e70-bc40-ed6e89bb293d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_8ca846bf-88f9-4a96-ba73-9c7e9481cd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_5cc538cb-b54e-4e70-bc40-ed6e89bb293d" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_8ca846bf-88f9-4a96-ba73-9c7e9481cd0e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_54818b92-9fe2-40bf-8c77-fc617c3b550d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_8ca846bf-88f9-4a96-ba73-9c7e9481cd0e" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_54818b92-9fe2-40bf-8c77-fc617c3b550d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_54818b92-9fe2-40bf-8c77-fc617c3b550d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_54818b92-9fe2-40bf-8c77-fc617c3b550d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_54818b92-9fe2-40bf-8c77-fc617c3b550d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_54818b92-9fe2-40bf-8c77-fc617c3b550d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_aad85a74-73fd-4d4c-8d5a-5da8e3f3bf5b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:to="loc_us-gaap_CostOfSalesMember_aad85a74-73fd-4d4c-8d5a-5da8e3f3bf5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_3415bbdc-ce58-4bf5-90d0-866b35046cab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_3415bbdc-ce58-4bf5-90d0-866b35046cab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_2b3f1eee-2635-4cf5-b51f-ce811f206cf3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_2b3f1eee-2635-4cf5-b51f-ce811f206cf3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_a9df9f7a-85d9-4696-918d-ed2ae48c5fc7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e0194ddd-b2ea-46bb-93db-36bf21e84dd9" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_a9df9f7a-85d9-4696-918d-ed2ae48c5fc7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_1a905115-95f7-446e-93ed-03b714ca995d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_5cc538cb-b54e-4e70-bc40-ed6e89bb293d" xlink:to="loc_us-gaap_ShareBasedCompensation_1a905115-95f7-446e-93ed-03b714ca995d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/ShareBasedCompensationScheduleofunvestedshareactivityDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#ShareBasedCompensationScheduleofunvestedshareactivityDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/ShareBasedCompensationScheduleofunvestedshareactivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2b90dd03-5085-4a33-af96-0550cd24ed9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e9684d48-f91d-43b7-b100-6e8ce900fcac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2b90dd03-5085-4a33-af96-0550cd24ed9d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e9684d48-f91d-43b7-b100-6e8ce900fcac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_bf4289a2-232c-4f2e-98b2-a721b0f9e596" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e9684d48-f91d-43b7-b100-6e8ce900fcac" xlink:to="loc_us-gaap_AwardTypeAxis_bf4289a2-232c-4f2e-98b2-a721b0f9e596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bf4289a2-232c-4f2e-98b2-a721b0f9e596_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_bf4289a2-232c-4f2e-98b2-a721b0f9e596" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bf4289a2-232c-4f2e-98b2-a721b0f9e596_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cba55bb2-04aa-4f68-a614-ef9e6d46e4a3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_bf4289a2-232c-4f2e-98b2-a721b0f9e596" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cba55bb2-04aa-4f68-a614-ef9e6d46e4a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_c9394d70-425b-41a0-8e80-ea41a26a176b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cba55bb2-04aa-4f68-a614-ef9e6d46e4a3" xlink:to="loc_us-gaap_RestrictedStockMember_c9394d70-425b-41a0-8e80-ea41a26a176b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_04ff268b-be69-426b-a516-f86d3f4bbc17" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cba55bb2-04aa-4f68-a614-ef9e6d46e4a3" xlink:to="loc_us-gaap_PerformanceSharesMember_04ff268b-be69-426b-a516-f86d3f4bbc17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2b90dd03-5085-4a33-af96-0550cd24ed9d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bc39b131-5202-4689-8412-e1c1faf30c78" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bc39b131-5202-4689-8412-e1c1faf30c78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_f1a87f5c-04fe-42dd-ada7-9e7dc6d9482a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_f1a87f5c-04fe-42dd-ada7-9e7dc6d9482a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_725a720f-1ca0-420e-860a-b261384b9198" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_725a720f-1ca0-420e-860a-b261384b9198" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_97db84e4-20b4-4125-a7d1-d6b5fa88b511" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_477231d6-ffba-4ade-bcdb-76dad1893845" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_97db84e4-20b4-4125-a7d1-d6b5fa88b511" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_1a57ba59-b1ed-4711-956f-1d6edabb9a17" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2b90dd03-5085-4a33-af96-0550cd24ed9d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_b06d7653-ae32-4e5d-b3ad-7cc611c34c4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_b06d7653-ae32-4e5d-b3ad-7cc611c34c4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_bacb3cac-1576-4a1d-8859-59b6a037f4a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_bacb3cac-1576-4a1d-8859-59b6a037f4a1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_67751c37-9eb6-462e-90b5-f05bb2547951" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_67751c37-9eb6-462e-90b5-f05bb2547951" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c3b88391-3492-4d1b-9ff7-778142c3832f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_682bf8a8-ac0b-4f6f-90b3-a575a0c24ca3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_c3b88391-3492-4d1b-9ff7-778142c3832f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_8ead855e-6489-4916-96cd-47d427f547e4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/IncomeTaxesDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#IncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/IncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_a612ac72-1553-43ae-9957-90a98b7929ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_c9f7132d-3755-4210-bda7-f3cfb8e3f29b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_a612ac72-1553-43ae-9957-90a98b7929ee" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_c9f7132d-3755-4210-bda7-f3cfb8e3f29b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_66b2ccb9-f1db-485c-a088-470b38d7f600" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_c9f7132d-3755-4210-bda7-f3cfb8e3f29b" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_66b2ccb9-f1db-485c-a088-470b38d7f600" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_66b2ccb9-f1db-485c-a088-470b38d7f600_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_66b2ccb9-f1db-485c-a088-470b38d7f600" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_66b2ccb9-f1db-485c-a088-470b38d7f600_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_a7687311-7b0e-4d7b-98ef-3a77b447e27c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_66b2ccb9-f1db-485c-a088-470b38d7f600" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_a7687311-7b0e-4d7b-98ef-3a77b447e27c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_FederalStateAndForeignMember_ad930c6f-9ffb-468e-8a16-4e319ac50d5f" xlink:href="skin-20250331.xsd#skin_FederalStateAndForeignMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_a7687311-7b0e-4d7b-98ef-3a77b447e27c" xlink:to="loc_skin_FederalStateAndForeignMember_ad930c6f-9ffb-468e-8a16-4e319ac50d5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_88d2066d-3a4d-4021-bdea-2a726291a515" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_a612ac72-1553-43ae-9957-90a98b7929ee" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_88d2066d-3a4d-4021-bdea-2a726291a515" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_7009d212-7e78-4c15-bc85-8f4259bb1506" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_a612ac72-1553-43ae-9957-90a98b7929ee" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_7009d212-7e78-4c15-bc85-8f4259bb1506" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/NetLossAttributabletoCommonStockholdersScheduleofantidilutivesecuritiesexcludedfromearningspersharecomputationDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#NetLossAttributabletoCommonStockholdersScheduleofantidilutivesecuritiesexcludedfromearningspersharecomputationDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/NetLossAttributabletoCommonStockholdersScheduleofantidilutivesecuritiesexcludedfromearningspersharecomputationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_1b41bef8-3b1e-4306-a92a-f9e5fb49cf56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_88109f3d-152e-49f3-8517-7a45388ce14c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_1b41bef8-3b1e-4306-a92a-f9e5fb49cf56" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_88109f3d-152e-49f3-8517-7a45388ce14c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_88109f3d-152e-49f3-8517-7a45388ce14c" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_7f90ef4f-6f33-4ba8-8d47-4a400b9d24ad" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertibleDebtSecuritiesMember_5c4f2278-647a-4451-ad7f-5b53c4a282dd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConvertibleDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:to="loc_us-gaap_ConvertibleDebtSecuritiesMember_5c4f2278-647a-4451-ad7f-5b53c4a282dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_28911d4b-f9a5-4d7d-bfac-335a1bb0ca0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_28911d4b-f9a5-4d7d-bfac-335a1bb0ca0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_fc86fb33-10f6-4786-abf5-569b1b079522" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:to="loc_us-gaap_EmployeeStockOptionMember_fc86fb33-10f6-4786-abf5-569b1b079522" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_67be60ac-fd95-4cca-9799-5c16338f9737" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_eccc36b1-71a6-4514-8a2d-0f77aa6eac15" xlink:to="loc_us-gaap_PerformanceSharesMember_67be60ac-fd95-4cca-9799-5c16338f9737" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_af2ebb80-a843-4348-bd52-b573de4b46a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_1b41bef8-3b1e-4306-a92a-f9e5fb49cf56" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_af2ebb80-a843-4348-bd52-b573de4b46a5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://hydrafacial.com/role/SegmentInformationComponentsofOperatingExpensesDetails" xlink:type="simple" xlink:href="skin-20250331.xsd#SegmentInformationComponentsofOperatingExpensesDetails"/>
  <link:definitionLink xlink:role="http://hydrafacial.com/role/SegmentInformationComponentsofOperatingExpensesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_035edac5-1146-4aea-81d3-5907b3ecf85f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_46280a64-00e5-42c2-9401-ab0d2aa33ab3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_035edac5-1146-4aea-81d3-5907b3ecf85f" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_46280a64-00e5-42c2-9401-ab0d2aa33ab3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_9561c59c-a139-4960-90b3-c6379ff7f2e5" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_46280a64-00e5-42c2-9401-ab0d2aa33ab3" xlink:to="loc_srt_ProductOrServiceAxis_9561c59c-a139-4960-90b3-c6379ff7f2e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_9561c59c-a139-4960-90b3-c6379ff7f2e5_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_9561c59c-a139-4960-90b3-c6379ff7f2e5" xlink:to="loc_srt_ProductsAndServicesDomain_9561c59c-a139-4960-90b3-c6379ff7f2e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_59bc574c-319e-43cd-878d-ab68e45435dc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_9561c59c-a139-4960-90b3-c6379ff7f2e5" xlink:to="loc_srt_ProductsAndServicesDomain_59bc574c-319e-43cd-878d-ab68e45435dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_PersonnelRelatedExpensesMember_21b68b09-f0e0-40ea-8633-3c3349f5e788" xlink:href="skin-20250331.xsd#skin_PersonnelRelatedExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_59bc574c-319e-43cd-878d-ab68e45435dc" xlink:to="loc_skin_PersonnelRelatedExpensesMember_21b68b09-f0e0-40ea-8633-3c3349f5e788" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_skin_OtherSegmentItemsMember_fb99f711-8d75-4932-a644-d7d12b84a722" xlink:href="skin-20250331.xsd#skin_OtherSegmentItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_59bc574c-319e-43cd-878d-ab68e45435dc" xlink:to="loc_skin_OtherSegmentItemsMember_fb99f711-8d75-4932-a644-d7d12b84a722" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_f11fd41d-df25-4013-8309-a4331c69ac62" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_035edac5-1146-4aea-81d3-5907b3ecf85f" xlink:to="loc_us-gaap_OperatingExpenses_f11fd41d-df25-4013-8309-a4331c69ac62" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
