Hoodia has become a popular weight loss product used to suppress appetite.

Hoodia is a succulent plant that grows in the South African desert and used by a tribe to curb appetite, quench thirst, increase endurance when on long hunting expeditions and when food is scarce. The plant's active ingredient has been identified as P57, and has been patented by PhytoPharm*. In an unpublished study by PhytoPharm, a small group of men took P57 (not the Hoodia plant) and cut back on calories and lost weight. At this time, no supplements contain the patented P57; therefore you are likely to get a product called Hoodia that contains little or none of the purported active ingredient. The Hoodia plant is now grown in many different regions but no one knows if the plants outside the Kalahari Desert have the same effect on the body. More significantly no one knows if Hoodia is safe, especially if used continuously. The tribesmen themselves rarely used it and not for weight loss. One of the original researchers from Pfizer cautioned "that P57 may have unwanted effects on the liver."

Due to the lack of published human research and safety data as well as the aforementioned uncertainty of the currently sold products' actual contents, we recommend you stay clear of any supplement claiming to contain Hoodia Gordonii.

*Hoodia's active ingredient is a steroidal glycoside, labeled P57AS3. The active component seems to exert its effects on the hypothalamus by increasing ATP activity. To date there has been only one published study on Hoodia gordonii, or more specifically P57. It involved injecting rats with P57 directly into the hypothalamus and then recording the effect on appetite. Rats injected with P57 decreased their food intake 50-60% over a 24-hour period.[i] The effect on appetite increased with a higher dose. Whether or not the decrease in appetite would result in weight loss is not known. After the initial 24-hour period (after injection), the rats were euthanized to study the effects of P57 on brain tissue.

[i] MacLean DB, Luo LG. 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 Res. 2004 Sep 10;1020(1-2):1-11.