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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2017-11-16</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001604950</issuerCik>
        <issuerName>scPharmaceuticals Inc.</issuerName>
        <issuerTradingSymbol>SCPH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001171005</rptOwnerCik>
            <rptOwnerName>SILVERSTEIN JONATHAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SCPHARMACEUTICALS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2400 DISTRICT AVENUE, SUITE 310</rptOwnerStreet2>
            <rptOwnerCity>BURLINGTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>18500000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By: OrbiMed Private Investments VI, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">All series of Convertible Preferred Stock will automatically convert into scPharmaceuticals Inc. common stock on a 7.180193-for-1 basis immediately prior to the closing of the initial public offering and have no expiration date.</footnote>
        <footnote id="F2">The shares of Series B Preferred Stock are held of record by OrbiMed Private Investments VI, L.P. (&quot;OPI VI&quot;).  OrbiMed Capital GP VI C (&quot;GP VI&quot;) is the sole general partner of OPI VI, and OrbiMed Advisors LLC (&quot;Advisors&quot;), a registered adviser under the Investment Advisers Act of 1940, as amended, is the sole managing member of GP VI.  Jonathan Silverstein, a natural person, is a is a managing members of, and holder of a controlling interest in Advisors.   The reporting person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest, if any, and this report shall not be deemed an admission that the reporting person is the beneficial owner of all of the reported shares for purposes of Section 16 or any other purpose.</footnote>
    </footnotes>

    <remarks>Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Courtney Gaughan, Attorney-in-Fact</signatureName>
        <signatureDate>2017-11-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
