<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-01-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0002023016</issuerCik>
        <issuerName>Turn Therapeutics Inc.</issuerName>
        <issuerTradingSymbol>TTRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002108597</rptOwnerCik>
            <rptOwnerName>Dewhurst Martin William</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TURN THERAPEUTICS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>250 N. WESTLAKE BLVD.</rptOwnerStreet2>
            <rptOwnerCity>WESTLAKE VILLAGE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91362</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-01-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>21882</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21882</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The securities reported in Column 5 of Table I are restricted stock units (&quot;RSU&quot;). Each RSU represents a contingent right to receive one share of common stock, subject to the applicable vesting schedule and conditions of the applicable RSU award and the Issuer's 2025 Omnibus Incentive Plan. The 21,882 RSUs included in Column 5 of Table I vest in full on January 7, 2027, subject to the reporting person's continuous service to the Issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Zuraiz Chaudhary, attorney-in-fact for Martin William Dewhurst</signatureName>
        <signatureDate>2026-02-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
