Citrus Aurantium, More commonly called "bitter orange", which is taken from unripe oranges. Research shows that citrus aurantium can increase the metabolic rate without affecting heart rate or blood pressure, breaks down fat, burns calories and may act as an appetite suppressant.

Hoodia Gordonii grows in Namibia and South Africa naturally. It is a leafless spiny plant useful for medicinal purposes. These flowers are pollinated by flies mainly as they smell identical to rotten meat. Hoodia is known long by indigenous population and is infrequently used for treating small infections and indigestion. This is used to suppress appetite during long hunting trips such as Kalahari Desert that interests more tourists. Hoodia Gordonii was prominent for it appetite suppressing effect and hence was collaborated with Pfizer, a pharmaceutical company to deal with obesity. However, it was stopped as it is stated to have indications of effects on liver. Hoodia Gordonii is wild harvested by individuals as well as by few companies that are granted license. However, there is no evidence of Hoodia working in humans as appetite suppressant. Due to the lack of clarity and fear of breaking down of liver, it is not recommended for obesity.