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The Prickly Truth: Is Hoodia really all it is hyped up to be?

Jennifer Davis

November 17, 2009

Imagine: A pill that keeps you from getting hungry, keeps you from craving food, and has no side effects except minor aphrodisiacal qualities. Many of the Xhomani San Bushmen of the Kalahari Desert know this feeling well.  Before they embark on long hunting excursions they eat a plant that keeps them from feeling hungry for days. The plant is called Hoodia gordonii and it grows naturally in the Kalahari Desert of South Africa, Namibia, and Botswana. This little cactus like plant is hardly a secret. There are hundreds of products, websites, and advertisements that exploit its weight loss properties, but how many of these claims are actually true?  I sought to investigate the effectiveness of the plant in curbing appetite and the research behind how it works. There is convincing evidence that Hoodia really does help with weight loss, but the biggest problem related to the herbal remedy is the validity of the products on the market. Some products contain the proper amount of active ingredient while other contain saw dust, so determining who and where to get the product from is a tricky process.

         History behind Hoodia: The Bushmen have lived in southern Africa for more than 100,000 years and Hoodia has always been part of their diet. In the African tradition it was used to suppress appetite, and to treat abdominal cramps, hemorrhoids, tuberculosis, and diabetes (Shukla, 2009, p. 675). In 1963, the National Food Research Institute in South Africa was investigating indigenous plants that were used as food (Van Heerden, 2008, p.434). They originally thought the plant would suppress thirst, but in a mouse study it significantly suppressed appetite as well. After 30 years of research, they isolated a previously unknown molecule they named P57 (Leung, 2004, CBS). They applied for a patient on the molecule and licensedit to a British pharmaceutical company, Phytopharm.


Text Box: San Bushmen, Kalahari Desert, Namibia
Photograph by Mark Read. National Geographic Channels International

     Does it really work? There have been numerous accounts from investigative journalists that Hoodia really does decrease appetite.   BBC’s Tom Mangold and CBS’s Lesley Stahl actually went to Africa, tried the plant, and experienced a significantly suppressed appetite. Both reporters said they were not hungry for at least a 24 hour period and they both described that they actually felt full. Mangold reported that he was not hungry until dinner next day, and when he did eat it was with “very little pleasure” (Mangold, 2003, BBC). Stahl was asked about her experience with the plant and reported “I’d have to say it did work” (Leung, 2004, CBS). These examples are only personal accounts, but valid scientific research is hard to find because Phytopharm holds the licensing for the plant, and they have not published any data (Stoppler, In a rat research study, Hoodia was found to decrease appetite by affecting cells in the hippocampus, which are related to the brain’s reward system. If the rats were starved, the levels of ATP in their hippocampus were depleted (MacLean, 2004, p.6). If they were given Hoodia the levels of ATP increased and mirrored that of control rats (MacLean, 2004,6). ATP levels in the hippocampus are typically controlled by glucose supplied in the diet. Hoodia has a similar structural component to glucose which may be why ATP levels are affected in this particular brain region. Another experiment in the same study injected rats with Hoodia daily and found that it markedly reduced their daily food intake and body fat content compared to controls. In the figure, food intake was found to be directly related to the amount of Hoodia active product P57AS3 the rats received intravenously (ICV). The more Hoodia the rats received the less they ate over a 24 hour period. The study also checked the functioning of other organs that might be affected by the plant or by glucose fluctuations, such as the brain, kidney, and liver, but they found no significant side effects. Phytopharm mentions a study using human volunteers on their website, but it has not been published. They claim that Hoodia decreased the daily caloric intake and the body fat of participants compared to controls ( It is interesting to note that Phytopharm only has a patient on the plant as a weight loss drug, not the plant itself (Leung, 2004, CBS). Therefore other studies have found other redeeming qualities to the plant such as antidiabetic qualities and the prevention of aspirin-induced gastric damage (Avula, 2006, ¶2).

      Where should I get it? Hoodia, although promising for weight loss, is very difficult to cultivate and a pill form is almost impossible to manufacture. Phytopharm has spent over $20 million on research already (Leung, 2004, CBS). Pfizer had originally funded most of the research with Phytopharm but recently dropped the project because they felt that a pill form was unrealistic to create (Stoppler, But why would it be so difficult? The natural supply of Hoodia is very limited. It has never been cultivated and it only grows in the wild. It is used to the extreme temperatures and conditions of the desert and it takes years to mature.  Technically the plant is now endangered and exports of Hoodia are strictly monitored by the South African government (Avula, 2006, ¶3). Anyone who exports the plant must have a CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) certificate. After Pfizer dropped the project, Phytopharm decided the original form of the plant would be the easiest to market. They started Hoodia plantations in southern Africa in hopes of meeting the market demand. Their plan is to add the plant extract to diet bars and shakes, but growing the plant mass quantities and in a plantation setting is proving to be very difficult.  

     Supply ≠ Demand: Obesity is a major problem in the United States and around the world, so the demand for an effective appetite suppressant is very high. Unfortunately the Hoodia supply is very scarce. This disparity has lead to the biggest problem facing Hoodia consumers today, counterfeiting. The FDA funded a research project that tested the 10 most popular Hoodia products in the U.S. for the active ingredient, P57 (Avula, 2006). Of the products tested, 8 of 10 samples contained no Hoodia at all. Of the two which actually contained P57, the level of active ingredient was drastically different between the two. One sample contained 0.17% of P57 and the other only had 0.0048%. Another group,, also uncovered a product scam through independent investigation ( ). Not only did they discover that some pills were filled with “silica, leaves, (and) sawdust” but some companies are producing fake comparison websites and tampering with previous scam publications. Mike Adams, the website’s “Health Ranger” estimates that more than 75% of all Hoodia gordonii supplements are fake (Adams, 2005 Aug). In the past he sent samples to independent research labs and had them tested for active P57, but as more and more manufacturers emerged it became too costly to run tests for every product on the market. Currently, there is no regulation for the amount of Hoodia that goes into a product, if any at all. Most individuals cannot afford to have their products tested and the lab itself could be tied to a specific manufacturer. CBS estimates that Americans spend over $40 billion a year trying to lose weight (Leung, 2004, CBS). So it is without question why Hoodia is selling for around $300 a kilogram, whether is it the real thing or not (Adams, 2005 Aug). Many websites are even faking CITES certificates with the help of computer programs such as Photoshop to add their product/company name (Adams, 2005 Aug).  Here are a few advertisements and the claims they make…

“The Hoodia brought to you by HoodiaP57 is one of the only forms of Hoodia that has been clinically tested in America. A clinical study showed that within 28 days: An average decrease in body fat of 3.3%. (And)An average 10 pounds of weight loss.” (


I searched for the research behind the clinical trial cited above and found a 2 page PDF article that actually used a separate Hoodia product “Hoodia Gordonii DEX-L10” for the experiment ( Aside from fact that the study was not run on the proper product, the research itself was very faulty and the study was unpublished. The experiment only used 7 participants, and it did not mention sex, height, age, previous medical conditions, whether or not the participants were compensated, how they were recruited, or what happened to their weight after the 28-day trial. The methods were poorly defined and there was very little statistical data. The same researchers are cited on various different Hoodia manufacturer websites for different products such as LookingTrim ( )and Herbalean ( I also found a website for an independent lab that tests Hoodia products ( On the lab website they endorsed their “3 top products” all of which were owned by the same companyPrime Life Neutriceuticals, Inc.” although they each had separate information, websites, phone numbers, and products the manufacturer was the same( ( (  Most of the research cited on Hoodia selling websites is not product specific, was not conducted by the companies themselves, and actually applies to previous studies where pure extracts of P57 were supplied by university laboratories or other botanical centers. The rat study funded by the FDA is cited on several websites but it used pure plant material from the Missouri Botanical Garden, not a particular Hoodia pill or product (Avula, 2006). Maybe the reason Phytopharm is waiting to publish their data is because many manufactures are stealing their research. Dr. Richard Dixey, the head of the Phytopharm company has described the prevalent information misuse as, “straightforward theft…people are stealing data, which they haven’t done, they’ve got not proper understanding of, and sticking it on a bottle”(Leung, 2004, CBS). Some manufacturers are still selling the same diet pills they have sold for years, only now they are calling it Hoodia instead. This may be why 8 of the 10 products tested in the research above contained no active ingredient whatsoever.

      Patience is a virtue: A this point in time Hoodia seems like it has a lot of potential to be a safe and effective weight loss drug, but I would not trust most of what is on the market today. Hopefully Phytopharm will publish their findings soon and actually start selling a product. But even if Phytopharm released conclusive evidence about the effectiveness of Hoodia tomorrow, it would still need FDA approval before it can be a trustworthy investment. If you are interested in finding the product and cannot wait for the FDA and Phytopharm, there are documents about export licensing on The South African National Biodiversity Institute website ( ). Unfortunately they do not list the manufacturers that actually have a CITES certificate, but even if they did it would not ensure that the manufacturers are actually using the claimed amount of active ingredient in their product. On this website you will also find instructions for growing the plant and what it looks like. So if you are serious enough about weight loss to move to Africa, obtaining a growing permit, and start a crop you will have all the information you need. A more practical option for people anxious to try Hoodia is to have a product tested by an independent lab. However, some of the labs are also involved in product scams, so a best friend who is an organic chemist (because we all have those) would be a more trustworthy option. Presently, there is not enough clinical research using human trials to determine if Hoodia is effective and safe, but hopefully that will change soon. In the meantime one of the biggest Hoodia issues remains. Who and where you buy your Hoodia product from could mean the difference in losing weight and taking a daily pill of weeds and sawdust.     


Adams, M. (2005, March 26) Consumer Alert: Hoodia Gordonii Weight Loss Pill Scam Exposed by Independent Investigation. Retrieved October 2, 2009, from

Adams, M. (2005, August 30) Diet Pill Supplement Scam: Two-Thirds of Hoodia Gordonii Pills Sold in United States Are Counterfeit. Retrieved October 2, 2009, from

Avula, B., Yan-Hong, W., Pawar, R. S., Shukla, Y. J., Schaneberg, B., Khan, I. A. (2006) Determination of the appetite suppressant P57 in Hoodia gordonii plant extracts and dietary supplements by liquid chromatography/electrospray ionization mass spectrometry. Journal of AOAC International, 89.3, 606-612.

Leung, R. (2004, Nov. 21) African Plant May Help Fight Fat. CBS News Online. Retrieved October 2,2009, from

MacLean, D. B., Luo, L. (2004). Increased ATP content/production in the hypothalamus may be a signal for energy-sensing of satiety: studies of the anorectic mechanism of a plant steroidal glycoside. Brain Research, 1020, 1-11.

Mangold, T. (2003, May 30) Sampling the Kalahari Cactus Diet. BBC News Online. Retrieved October 2, 2009, from 

Shukla, Y. J., Pawar, R. S., Ding, Y., Li, X., Ferreira, D., Khan, I. A. (2009) Pregnane glycosides from Hoodia gordonii. Phytochemistry, 70, 675-683.  

Stoppler, M. C. Hoodia, The New Weight Loss Miracle? Retrieved October 2, 2009, from  

Van Heerden, F. R. (2008). Hoodia gordonii: A natural appetite suppressant. Journal of Ethnopharmacology, 119, 434-437.




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