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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-07-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001100962</issuerCik>
        <issuerName>ENDO HEALTH SOLUTIONS INC.</issuerName>
        <issuerTradingSymbol>ENDP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001554635</rptOwnerCik>
            <rptOwnerName>Farhat Camille</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AMERICAN MEDICAL SYSTEMS</rptOwnerStreet1>
            <rptOwnerStreet2>10700 BREN ROAD WEST</rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55343</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, AMS, Inc.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>2010 Stock Incentive Plan Performance Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2013-07-01</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2013-07-08</value>
                <footnoteId id="F2"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7296</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7296</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The performance shares vest upon the Company achieving certain shareholder return targets over a cumulative 3-year period.</footnote>
        <footnote id="F2">The deemed execution date represents the date on which the reporting person was notified of the number of performance shares granted on July 1, 2013. Accordingly, pursuant to Rule 16a-3(g)(3), the deemed execution date was July 8, 2013.</footnote>
        <footnote id="F3">Represents target quantity of shares issuable. The exact number of shares issuable will be determined on achievement of certain shareholder return targets over a cumulative 3-year period, as determined by the Board of Directors of Endo Health Solutions Inc. The executive can earn between 0% and 300% of the target shares.</footnote>
        <footnote id="F4">These securities were granted to Mr. Farhat in consideration of his services as President of American Medical Systems, a subsidiary of Endo Health Solutions Inc.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Caroline B. Manogue, by power of attorney</signatureName>
        <signatureDate>2013-07-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
