AMENDMENT TO MANUFACTURING SALES AGREEMENT

MANNATECH US and NAI are the current parties to a Manufacturing Sales Agreement dated November 19, 2004 (the “Manufacturing Agreement”);

MANNATECH SWISS is an affiliate of MANNATECH US; MANNATECH US is implementing a global restructuring project to optimize its operations and the restructuring includes adding MANNATECH SWISS as a party to certain supply and purchasing agreements; and

The parties, therefore, desire to amend and revise the Manufacturing Agreement for the purpose of adding MANNATECH SWISS as an additional party. Any capitalized terms used in the Amendment shall, unless otherwise specified herein, have the same meaning ascribed to such terms as set forth in the Manufacturing Agreement.

Amendment to Manufacturing Agreement. The Manufacturing Agreement is amended to provide that MANNATECH SWISS is added as a party to the Manufacturing Agreement. Thus, collectively and individually MANNATECH US and MANNATECH SWISS are entitled to receive all rights and benefits of Buyer under the Manufacturing Agreement and shall be responsible for all duties and obligations of Buyer under the Manufacturing Agreement. Except as contemplated under this Amendment, all other terms, conditions, provisions contained in the Manufacturing Agreement remain unchanged and in full force and effect.

Integration; Modification. This Amendment contains the entire understanding between NAI on the one hand, and MANNATECH US and MANNATECH SWISS on the other hand, with respect to the subject matter of this Amendment and this Amendment supersedes all prior or contemporaneous oral or written agreements, conditions, or representations. This Amendment may not be amended, canceled, or superseded, nor will any provision of this Amendment be deemed waived, except by a written instrument executed by each of the parties to be charged.

Binding Effect. This Amendment will be binding upon, and inure to the benefit of, the parties and their respective heirs, legatees, personal representatives, successors and assigns.

Counterparts. This Amendment may be executed in one or more counterparts, each of which will be deemed an original, but all of which, when taken together, will constitute one and the same instrument.