Hoodia Gordonii is a South African succulent plant of the family Apocynaceae. They are remarkable similar in appearance to cacti, although they are totally unrelated to them and grow predominantly in the region of Central Namibia in the south west of Africa, up to the southern regions of Angola. They are most commonly found in rocky ground and on the plains.

There are several species of Hoodia, some of them grown domestically, and it is Hoodia Gordonii that is used as an appetite suppressant in Hoodia weight loss pills. Although the plant has historically found use in the treatment of infections and gastric problems, most interest is displayed in its use by the bushmen of the Kalahari Desert to suppress their appetite during long hunting trips when food and water are scarce.

The active ingredient was isolated in 1977, and given the name P57: the product is therefore often referred to as Hoodia P57. It was patented by its discoverers, the CSIR (South African Council for Scientific and Industrial Research) and a license granted to UK company Phytopram, who worked together with Pfizer to isolate the active ingredients and manufacture them synthetically. This was found to be very difficult, if not impossible, since any synthetic form of the extract failed to display any hunger-suppressant properties.