Investigation of Hoodia gordonii as an appetite suppressant
The use of Hoodia has been long known by the indigenous populations of Southern Africa, who infrequently use these plants for treating indigestion and small infections.
In 1977, the South African Council for Scientific and Industrial Research (CSIR) isolated the ingredient in hoodia (now known as P57) responsible for this appetite-suppressant effect and patented it. The CSIR then granted United Kingdom-based Phytopharm a license, and they collaborated with the pharmaceutical company Pfizer to isolate active ingredients from the extracts and look into synthesizing them for use as an appetite suppressant. Pfizer released the rights to the primary ingredient in 2002. Paul Hutson, associate professor in the University of Wisconsin-Madison School of Pharmacy, told the Wisconsin State News, "For Pfizer to release something dealing with obesity suggests to me that they felt there was no merit to its oral use". Pfizer states that development on P57, the active ingredient of Hoodia, was stopped due to the difficulty of synthesizing P57. Jasjit Bindra, lead researcher for Hoodia at Pfizer, states there were indications of unwanted effects on the liver caused by other components, which could not be easily removed from the supplement, adding "Clearly, Hoodia has a long way to go before it can earn approval from the Food and Drug Administration. Until safer formulations are developed, dieters should be wary of using it."
In 2002, CSIR officially recognized the San tribespeople’s rights over Hoodia, allowing them to take a percentage of the profits and any spin-offs resulting from the marketing of Hoodia. Hoodia gordonii is a protected plant which can only be wild-harvested by individuals and the few companies who have been granted a license.
Published scientific reports
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One scientific study has been published in which the extract was injected directly into the brains of rats. No published peer-reviewed double-blind clinical trials have been performed on humans to investigate the safety or effectiveness of Hoodia gordonii in pill form as a nutritional supplement. The author of the rat study said that P57 was easily broken down by the liver, so it might be hard to take in enough of it to ensure that it had an effect. MacLean cautioned that currently available supplements might be inadequate, stating "I question whether there is really enough of the active ingredient in there to do much."
Press coverage
The press coverage and heavy marketing by nutritional supplement companies have created such a demand for Hoodia plants that a protected status was imposed in several countries like Namibia. Many products claiming to contain Hoodia do not actually contain the active ingredient alleged to suppress appetite. Only the South African product has the claimed properties. An ongoing review of Hoodia pills by Alkemists Pharmaceuticals found that at least half of the products advertised as containing Hoodia contained none.
In 2004, 60 Minutes correspondent Lesley Stahl traveled to Africa to try Hoodia gordonii for herself. According to Stahl, she did not have a normal "pang around mealtime," concluding, "I'd have to say it did work." A BBC correspondent presented a similar anecdotal report in 2003
In March 2006, Consumer Reports investigated the dietary supplement and concluded, "This weight loss drug lacks the clinical evidence for the Consumer Reports experts to recommend this product."
