<SEC-DOCUMENT>0001056358-18-000028.txt : 20180329
<SEC-HEADER>0001056358-18-000028.hdr.sgml : 20180329
<ACCEPTANCE-DATETIME>20180329143639
ACCESSION NUMBER:		0001056358-18-000028
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160204
FILED AS OF DATE:		20180329
DATE AS OF CHANGE:		20180329

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Fredrick Landen Granvel
		CENTRAL INDEX KEY:			0001666982

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24657
		FILM NUMBER:		18722404

	MAIL ADDRESS:	
		STREET 1:		600 S. ROYAL LANE
		STREET 2:		SUITE 200
		CITY:			COPPELL
		STATE:			TX
		ZIP:			75019

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:		600 SOUTH ROYAL LANE
		STREET 2:		SUITE 200
		CITY:			COPPELL
		STATE:			TX
		ZIP:			75019
		BUSINESS PHONE:		9724717400

	MAIL ADDRESS:	
		STREET 1:		600 SOUTH ROYAL LANE
		STREET 2:		SUITE 200
		CITY:			COPPELL
		STATE:			TX
		ZIP:			75019
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>wf-form3a_152234858601336.xml
<DESCRIPTION>FORM 3/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2016-02-04</periodOfReport>

    <dateOfOriginalSubmission>2016-02-16</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001666982</rptOwnerCik>
            <rptOwnerName>Fredrick Landen Granvel</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>600 S. ROYAL LANE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>COPPELL</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock Par Value $0.0001 Per Share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1975</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The original Form 3 filed on February 16, 2016 did not report the number of non-derivative securities directly owned by the reporting person as of such date. The correct number of non-derivative securities directly owned by the reporting person as of February 16, 2016 was 1,975.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Diane Barton, Controller, by Power of Attorney</signatureName>
        <signatureDate>2018-03-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
