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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-08-31</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001233426</issuerCik>
        <issuerName>NationsHealth, Inc.</issuerName>
        <issuerTradingSymbol>NHRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001019190</rptOwnerCik>
            <rptOwnerName>MHR CAPITAL PARTNERS LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>40 WEST 57TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>24TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Former 10% Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001284082</rptOwnerCik>
            <rptOwnerName>MHR ADVISORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>40 WEST 57TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>24TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Former 10% Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <remarks>The Reporting Persons are eligible to voluntarily file this exit Form 4 because, following the Issuer's issuance of additional shares of common stock upon the consummation on August 31, 2004 of a merger among the Issuer (formerly known as Millstream Acquisition Corporation), NationsHealth Holdings, L.L.C. and N Merger L.L.C. (a wholly-owned subsidiary of the Issuer), each Reporting Person beneficially owns less than 10% of the outstanding shares of common stock of the Issuer.</remarks>

    <ownerSignature>
        <signatureName>Hal Goldstein, as Vice President of MHR Advisors LLC, as General Partner of MHR Capital Partners LP</signatureName>
        <signatureDate>2004-09-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hal Goldstein, as Vice President of MHR Advisors LLC</signatureName>
        <signatureDate>2004-09-20</signatureDate>
    </ownerSignature>
</ownershipDocument>

