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William T. Jarvis, Ph.D.

Mannatech, a multilevel marketing health products firm, is promoting itself as a "nutraceutical frontrunner." "Nutraceutical" is a marketing term for foods alleged to favorably alter the structure or function of the body beyond what normal foods can accomplish. The company's lead product, Manapol, is simply aloe vera juice. Mannatech promoters acknowledge that many counterfeit products emerged during past aloe vera fads, but they claim that this juice is the real thing.

It is generally acknowledged that breaking off a leaf from a living aloe vera plant and applying the juice to a burn is an excellent first aid measure. Aloe vera juice is also used in burn wards to soothe, protect and moisten wounds. The problem with marketing the juice is that it doesn't keep well. Processing inactivates the ingredient that produces the desired effects. So, many aloe vera products contain processed juice that has lost the plant's helpful properties.

According to Mannatech's literature, aloe vera expert Ivan Danhof, PhD, MD, warned aloe promoters about making claims, and on the instability of beta-1,4-mannan molecules. Mannatech says that the "future of aloe vera belongs to those who have the ability to stabilize and standardize (emphasis added) this labile polysaccharide," and that Manapol is the "only commercially processed aloe vera product capable of achieving and make the claim for standardizing betamannans."

Mannatech has a licensing agreement with Carrington Laboratories, an aloe processor that has a jaded history on Wall Street in connection with its product Carrisyn. Carrisyn was said to have an Investigational New Drug (IND) permit from the FDA as a topical gel for treating bedsores. Carrington also announced that it had filed for patents in 43 countries for Carrisyn and that the drug might be useful for AIDS. AIDS is a buzzword that sends stocks flying. However, the FDA denied that it had issued an IND for Carrisyn. It had only assigned a number to Carrington's IND application. All of this produced quite a stink among investment watchdogs, which was detailed in two reports in Barron's [1,2].

NCRHI believes that extreme caution is advised on Mannatech. Mannatech's President Caster has a checkered history. In 1991, his Eagle Shield Inc. claimed its Electracat device would repel insects and other pests by emitting high-frequency vibrations. The Texas Attorney General disagreed. "The device is a hoax and stands on the same scientific footing as a perpetual motion machine," said Assistant Attorney General William Goodman, who won a permanent injunction against Caster and Eagle Shield in Travis County District Court. Caster agreed to stop selling the Electracat, to not make unsupported scientific claims about any other product, and to pay $125,000 in investigative costs. Two years earlier, Caster and Eagle Shield were accused of deceiving consumers by claiming their Eagle Shield Radiant Barrier was a scientific breakthrough in home insulation and would provide significant savings in energy costs. The Texas Attorney General got a court order banning such claims after arguing the product had been available for more than 40 years and that the energy-saving claims were false. Caster and the company agreed not to make more false statements, and Eagle Shield filed for Chapter 11 bankruptcy protection. Caster co-founded Mannatech in 1993.

Mannatech tells consumers scientific studies show its nutritional supplements are safe, promote good health and are even covered by a health insurance plan. Investors have been given another story. In documents for its initial public stock sale in February, 1999, Mannatech told potential buyers it doesn't know whether its products were safe, or even if they worked. Yet Stephen Boyd, a physician who is Mannatech's international medical director, praises its supplements in a recorded message for prospective customers. He says the products facilitate the body's ability to heal itself and are "inherently non-toxic." Coppell, Texas-based Mannatech warned in the share-sale prospectus, however, that there is no assurance its products, "even when used as directed, will have the effects intended, or will not have harmful side effects."

"Why are they telling consumers one thing and investors another?" asked Stephen Barrett, M.D, chairman of Quackwatch Inc., a not-for-profit organization that monitors healthcare fraud. "A company has a responsibility to determine its products are safe and effective before it sells them." Company executives declined to comment about the products, which are sold through more than 400,000 independent agents in the United States and in Australia. In its IPO filing, Mannatech cautioned investors that its MVP product, marketed for weight control, contains ephedrine, a substance the FDA has linked to heart attacks, strokes and death. There are no warnings in the company's literature for consumers about MVP. The FDA, which has received more than 800 reports of adverse events associated with ephedrine, has proposed banning its sale for weight control.

While Mannatech says it has an eight-member scientific team, its monthly magazine recently said there are no double-blind, placebo-controlled studies of the type used by drug companies establishing that its products work. It said it that between 1995 and 1997, it spent about $667,000 (0.25% of sales) on research. The company offers consumers insurance called MannaCare that reimburses up to 50% of the cost of its supplements. It also provides full medical, dental and vision coverage for premiums of up to $9,120 annually. The insurance is offered through U.S. Alliance, a Crofton, Maryland, insurer that said it's unlicensed in the state. "There wasn't an insurer they met with in the last three years that would reimburse" for Mannatech products, said Walter Nieves, president of U.S. Alliance. "That's why they came to me." Nieves said he doesn't need a license because his plan is exempt from state regulation.

NCAHF has been concerned about Mannatech because of reports it has received that cancer patients are being advised to use its products as part of their cancer treatment. There is no good reason to believe that aloe vera products would be an effective anticancer agent. In fact, aloe vera latex failed to show an anticancer effect [3]. From the consumer conversations it seems that overzealous salespeople are going overboard in their enthusiasm for their products. Even if aloe vera products are good sources of dietary fiber (aloe gel contains a substance similar to guar gum, it would not make them appropriate for cancer patients under radiation or chemotherapeutic treatment. Because of impaired absorption, such patients generally require highly concentrated nutritional formulas, not high-fiber foods. If fiber plays any role at all in cancer management, it would more likely be in the prevention of the disease, not treatment. It is not clear at this time the extent to which the company is aware that some of its distributors are making inappropriate claims regarding cancer. NCRHI has seen a common pattern of excessive health claims by multilevel marketing distributors whose imaginations run away with them in their enthusiasm for their products. Companies often try to distance themselves from such claims, but rarely do anything to effectively control such abuses. For more see NCAHF's consumer information statement "Multilevel Marketing."

Some of the "medical experts" that Mannatech has employed in its promotions have brought discredit upon the company. A naturopath, "Dr." Stephen Nugent, has been used by the company in videos and major events. According to his own curriculum vitae, Nugent's naturopathic diploma was obtained from the Clayton School of Natural Healing, a diploma mill operated by Lloyd Clayton of Birmingham, Alabama. Clayton also operates Chadwick University and the American Holistic College of Nutrition. He also sells "Dr. Clayton's herbals and homeopathics." Although the Clayton "schools" operate in Alabama, they are not licensed there. Alabama's Department of Education attempted to close Clayton down in 1981 but was no successful. The State Attorney General opined that the "schools" would not be required to be licensed if they offered no programs to Alabama citizens. [Joe Miller, Private School Licensure Section, Alabama Dept of Education, letter 9/18/95].

Mannatech also used a questionable physician in its promotions, but it is possible that the company can be considered somewhat of a victim in this case. Dr. Darryl See claimed to have done a study that ranked Mannatech's pills, including its flagship product Ambrotose, in the top five of 196 nutritional supplements tested. See recommended Mannatech's supplements for treatment of diseases such as AIDS and cancer in an audio cassette distributed by the company. However, on August 20, 1999 Mannatech said it has cut all ties to See, and is considering a lawsuit against him, because he backed his claims with false documents. A company investigation confirmed a Bloomberg News report that See's study was neither funded by the National Institutes of Health nor conducted under the auspices of the University of California at Irvine medical school, as it claimed. "We have disassociated ourselves completely and unequivocally from Dr. See," said Samuel Caster, Mannatech's president. Mannatech also quoted from a Bloomberg News report in which Marikel Chatard, the technician who See said did most of the lab tests for the study, denied participating in it. The company said it verified Dr. See's claims before using the his study. "We did everything we possibly could to ensure the material was authentic," Caster added. That included paying $30,000 for an audit of See's study, which it previously used to defend it. Bloomberg News reported that See never provided the laboratory notebooks requested by the auditor to authenticate his data. Mannatech paid See more than $100,000 to speak at sale rallies and conduct research, and that his wife has been a Mannatech distributor since 1997, as See told Bloomberg in an interview. Mannatech sells its pills through an army of more than 400,000 distributors. Company executives weren't available for comment. See resigned from the university's faculty after an investigation censured him for violating research rules, including falsifying documents and conducting laboratory experiments on a rabbit without sufficient anesthesia. The Journal of the American Nutraceutical Association, which published See's article, has stopped selling reprints of See's articles, books, and videotapes.

Portions of this article were adapted from a series of articles by David Evans (Bloomberg News) that is posted in full on MLM Watch Web site.


  1. Up & Down Wall Street Barron's 9/22/86
  2. Up & Down Wall Street Barron's 9/29/86.
  3. Aloe, Lawrence Review of Natural Products April, 1992.

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This article was posted on January 15, 2001.