FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Clark Natalie Lynne   2. Issuer Name and Ticker or Trading Symbol MANNATECH INC [MTEX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Sr VP North American Sales (Last) (First) (Middle) 600 S ROYAL LN #200 3. Date of Earliest Transaction (Month/Day/Year) 08/13/2010 (Street) COPPELL, TX 75019 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Right to Purchase Common Stock

$ 14.99

08/13/2010

D

12,000

(1)

11/16/2016

Common Stock, Par Value $0.0001 per share

12,000

$ 0 (4)

38,000

D

Right to Purchase Common Stock

$ 7.31

08/13/2010

D

3,000

(2)

09/05/2017

Common Stock, Par Value $0.0001 per share

3,000

$ 0 (5)

35,000

D

Right to Purchase Common Stock

$ 2.63

08/13/2010

D

4,000

(3)

08/22/2010

Common Stock, Par Value $0.0001 per share

4,000

$ 0 (6)

31,000

D

Right to Purchase Common Stock

$ 2.46

08/16/2010

A

7,190

(7)

08/15/2020

Common Stock, Par Value $0.0001 per share

7,190

$ 0

38,190

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Clark Natalie Lynne 600 S ROYAL LN #200 COPPELL, TX 75019			Sr VP North American Sales

Signatures

/s/ Stephen D. Fenstermacher, Co-CEO and CFO, by Power of Attorney		08/17/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The option provided for vesting in three equal annual installments beginning November 17, 2007.
(2)	The option provided for vesting in three equal annual installments beginning September 6, 2008.
(3)	The option provided for vesting in three equal annual installments beginning August 23, 2001.
(4)	On August 16, 2010, the issuer canceled, pursuant to the issuer's option exchange program, an option for 12,000 shares of Mannatech common stock granted to the reporting person on November 17, 2006. In exchange, the reporting person received a replacement option, for 4,016 shares, having an exercise price of $2.46 a share.
(5)	On August 16, 2010, the issuer canceled, pursuant to the issuer's option exchange program, an option for 3,000 shares of Mannatech common stock granted to the reporting person on September 6, 2007. In exchange, the reporting person received a replacement option, for 1,720 shares, having an exercise price of $2.46 a share.
(6)	On August 16, 2010, the issuer canceled, pursuant to the issuer's option exchange program, an option for 4,000 shares of Mannatech common stock granted to the reporting person on August 23, 2000. In exchange, the reporting person received a replacement option, for 1,454 shares, having an exercise price of $2.46 a share.
(7)	The option vests in three equal annual installments beginning August 16, 2011.

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