02/22/2011

Mannatech Schedules Fourth Quarter 2010
Earnings Release and Conference Call

(COPPELL, Texas) February 22, 2011 – Mannatech, Incorporated (NASDAQ: MTEX), a
leading developer and provider of nutritional supplements and skin care products based on Real
Food Technology® solutions, announced today that its financial results for the fourth quarter of
2010 will be released on Wednesday, March 9, 2011, after the NASDAQ market closes.
Mannatech will host a conference call to discuss the quarter’s results with investors on
Thursday, March 10, 2011 at 9 a.m. CST, 10 a.m. EST. The live call will be webcast and can
be accessed on Mannatech’s website at http://ir.mannatech.com.

For those unable to listen to the live broadcast, a replay will be available shortly after the call.
The toll-free replay number is 800-642-1687 (International: 706-645-9291); the Conference ID to
access the call is 38763154.

Individuals interested in Mannatech’s products or in exploring its business opportunity can learn
more at mannatech.com.

About Mannatech
Mannatech, Incorporated, develops high-quality health, weight and fitness, and skin care products that
are based on the solid foundation of nutritional science and development standards. These proprietary
products are available through independent sales Associates around the globe including the United
States, Canada, South Africa, Australia, New Zealand, Austria, Denmark, Germany, Norway, Sweden, the Netherlands, the United Kingdom, Japan, Taiwan, Singapore, the Republic of Korea and Mexico. For
more information, visit mannatech.com.

Please Note: This release contains “forward-looking statements” within the meaning of Section 27A of theSecurities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended,and the Private Securities Litigation Reform Act of 1995. These forward-looking statements generally can be identified by use of phrases or terminology such as “intend” or other similar words or the negative of such terminology. Similarly, descriptions of Mannatech’s objectives, strategies, plans, goals or targets contained herein are also considered forward-looking statements. Mannatech believes this release should be read in conjunction with all of its filings with the United States Securities and Exchange Commission and cautions its readers that these forward-looking statements are subject to certain events, risks, uncertainties, and other factors. Some of these factors include, among others, Mannatech’s inability to attract and retain associates and members, increases in competition, litigation, regulatory changes, and its planned growth into new international markets. Although Mannatech believes that the expectations, statements, and assumptions reflected in these forward-looking statements are reasonable, it cautions readers to always consider all of the risk factors and any other cautionary statements carefully in evaluating each forward-looking statement in this release, as well as those set forth in its latest Annual Report on Form 10-K and Quarterly Report on Form 10-Q, and other filings filed with the United States Securities and Exchange Commission, including its current reports on Form 8-K. All of the forward-looking statements contained herein speak only as of the date of this release.

MEDIA CONTACT
Allison Lowe Burum
(972) 499-6631
Allison.Lowe@hck2.com
ir@mannatech.com