GEL: amended insider filing

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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4/A</documentType>

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

    <dateOfOriginalSubmission>2026-07-02</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001022321</issuerCik>
        <issuerName>GENESIS ENERGY LP</issuerName>
        <issuerTradingSymbol>GEL</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001403412</rptOwnerCik>
            <rptOwnerName>Davison James E. Jr.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>2000 FARMERVILLE HIGHWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RUSTON</rptOwnerCity>
            <rptOwnerState>LA</rptOwnerState>
            <rptOwnerZipCode>71270</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Units - Class A</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5410284</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4/A amends the Reporting Person's Form 4 filed 07/02/2026 ('Original Form 4') solely to correct reported holdings of Common Units-Class A. As reported on the Reporting Person's 05/26/2026 Form 4, on 05/21/2026 the Reporting Person became the direct owner of 1,527,239 Common Units-Class A previously held directly by the Trusts and Special Trust (as defined in the Original Form 4), which thereafter held none. The Original Form 4 inadvertently continued to report those units as indirectly owned through the Trusts and the Special Trust. As corrected, the Reporting Person directly owned 5,410,284 Common Units-Class A following the reported transactions. Phantom unit transactions reported on the Original Form 4 were correctly reported and are not being re-reported. The same error was carried forward in the Reporting Person's Form 4 filed 10/02/2026 and the holdings reported in that Form 4 should be read as corrected by this Form 4/A.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>James E. Davison, Jr.</signatureName>
        <signatureDate>2026-10-13</signatureDate>
    </ownerSignature>
</ownershipDocument>