<SEC-DOCUMENT>0001056358-21-000109.txt : 20211201
<SEC-HEADER>0001056358-21-000109.hdr.sgml : 20211201
<ACCEPTANCE-DATETIME>20211201143059
ACCESSION NUMBER:		0001056358-21-000109
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211129
FILED AS OF DATE:		20211201
DATE AS OF CHANGE:		20211201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BALA ALFREDO
		CENTRAL INDEX KEY:			0001414010

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24657
		FILM NUMBER:		211462536

	MAIL ADDRESS:	
		STREET 1:		28 CITY VIEW CIRCLE
		CITY:			NORTH PROVIDENCE
		STATE:			RI
		ZIP:			02911

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_163838704722029.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-11-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001414010</rptOwnerCik>
            <rptOwnerName>BALA ALFREDO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1410 LAKESIDE PARKWAY, SUITE 200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FLOWER MOUND</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75028</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO and President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1150</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.70</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5630</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Right to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15.7</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-11-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1150</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.70</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-04-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.0001 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1150.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22850</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One-third of the stock options vest on the date of grant, another one-third of the stock options vest on the first anniversary of the date of grant, and the remaining one-third of the stock options vest on the second anniversary of the date of grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Diane Barton, Controller, by Power of Attorney</signatureName>
        <signatureDate>2021-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
