<SEC-DOCUMENT>0001056358-19-000108.txt : 20191127
<SEC-HEADER>0001056358-19-000108.hdr.sgml : 20191127
<ACCEPTANCE-DATETIME>20191127160852
ACCESSION NUMBER:		0001056358-19-000108
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20191126
FILED AS OF DATE:		20191127
DATE AS OF CHANGE:		20191127

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			FREDRICK J STANLEY
		CENTRAL INDEX KEY:			0001161280

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24657
		FILM NUMBER:		191257923

	MAIL ADDRESS:	
		STREET 1:		1601 BRYAN STREET
		STREET 2:		30TH FLOOR
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75201

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MANNATECH INC
		CENTRAL INDEX KEY:			0001056358
		STANDARD INDUSTRIAL CLASSIFICATION:	MEDICINAL CHEMICALS & BOTANICAL PRODUCTS [2833]
		IRS NUMBER:				752508900
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1410 LAKESIDE PARKWAY
		STREET 2:		SUITE 200
		CITY:			FLOWER MOUND
		STATE:			TX
		ZIP:			75028
		BUSINESS PHONE:		9724717400

	MAIL ADDRESS:	
		STREET 1:		1410 LAKESIDE PARKWAY
		STREET 2:		SUITE 200
		CITY:			FLOWER MOUND
		STATE:			TX
		ZIP:			75028
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_157488891543771.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-11-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001056358</issuerCik>
        <issuerName>MANNATECH INC</issuerName>
        <issuerTradingSymbol>MTEX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001161280</rptOwnerCik>
            <rptOwnerName>FREDRICK J STANLEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1410 LAKESIDE PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>FLOWER MOUND</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75028</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock Par Value $0.0001 Per Share</value>
            </securityTitle>
            <transactionDate>
                <value>2019-11-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.4725</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>208439</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions. The prices for the transactions range from $16.4195-16.4964. The reporting person undertakes to provide Mannatech, Incorporated, any security holder of Mannatech, Incorporated, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this Form 4.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/S/ David Johnson, Chief Financial Officer by Power of Attorney</signatureName>
        <signatureDate>2019-11-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
