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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-02-24</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001506492</issuerCik>
        <issuerName>Nuwellis, Inc.</issuerName>
        <issuerTradingSymbol>NUWE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001455136</rptOwnerCik>
            <rptOwnerName>McDonald David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12988 VALLEY VIEW ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EDEN PRAIRIE</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55344</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Nonstatutory Stock Option</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.32</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2034-01-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Nonstatutory Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.36</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-05-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>416</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person was a member of the Board of Directors (the &quot;Board&quot;) of the Issuer from November 1, 2023 until January 21, 2026, and filed an initial Form 3 on November 1, 2023.  He was reappointed to the Board on February 24, 2026.</footnote>
        <footnote id="F2">The option is fully vested.</footnote>
        <footnote id="F3">Vests in 12 approximately equal consecutive monthly increments, commencing on the one-month anniversary of the date of grant, so that all of the options will be vested on the one-year anniversary of the date of grant.</footnote>
    </footnotes>

    <remarks>Exhibit 24, Power of Attorney, is attached.</remarks>

    <ownerSignature>
        <signatureName>/s/ Neil P. Ayotte, by Power of Attorney</signatureName>
        <signatureDate>2026-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
