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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-11-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001894525</issuerCik>
        <issuerName>Apimeds Pharmaceuticals US, Inc.</issuerName>
        <issuerTradingSymbol>APUS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001573840</rptOwnerCik>
            <rptOwnerName>O'DONNELL CAROL A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O APIMEDS PHARMACEUTICALS US, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 MATAWAN ROAD, SUITE 325</rptOwnerStreet2>
            <rptOwnerCity>MATAWAN</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07747</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.67</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-11-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-11-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of common stock subject to the option shall vest in quarterly installments beginning October 1, 2025, such that the award shall be fully vested after three years subject to the reporting person's employment continuing through and on each vesting date. This option is not exercisable until stockholder approval is obtained to approve an amendment to the Company's incentive plan (the &quot;Plan&quot;) to increase the number of shares of common stock available for issuance under the Plan. The shares of common stock subject to the option shall vest in full vest upon the occurrence of a Change in Control, as defined in the Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Nelson Mullins Riley &amp; Scarborough LLP, Attorney-in-Fact</signatureName>
        <signatureDate>2025-11-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
