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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-03-08</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>Assumed Stock Incentive Plan Performance Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2013-03-08</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2013-03-13</value>
                <footnoteId id="F2"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5854</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5854</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 by the Board of Directors of Endo Health Solutions Inc. on March 8, 2013. Accordingly, pursuant to Rule 16a-3(g)(3), the deemed execution date was March 13, 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>2013-03-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
