Garcinia cambogia (also known as vriksh amla, kankushta, or Malabar tamarind) is a medium to large evergreen tree native to tropical regions of Asia. The tree has oblong, leathery leaves with pronounced central veins from which stem numerous delicate, horizontal veins. A member of the tamarind family, garcinia's pumpkin-shaped fruit is roughly the size of an orange, and is usually yellow or red (and rarely, purple) in color. The ripe fruit is generally too acidic to be consumed by itself, but is often used as a spice.
For centuries, garcinia fruit has been used in foods in many areas of tropical Asia. In Thai and Indian cuisines, garcinia is used in curries and other dishes as a condiment, often in place of limes or tamarinds. Valued by ancient Ayurvedic healers as a digestive aid, garcinia has recently become popular as a natural appetite suppressant.
The rind of the garcinia fruit contains 16 to 30 percent hydroxycitric acid (HCA), along with other fruit acids.
In vitro studies have shown that HCA inhibits the activity of ATP citrate-lyase, an enzyme involved in the conversion of sugars into fats. These studies, along with others in which HCA supplementation reduced food intake in laboratory rats, have led to popular use of garcinia as a weight-loss aid. However, there is no evidence that HCA inhibits fat production in humans. In fact, a 1998 study conducted on 135 overweight men and women found HCA to be no more effective than placebo in reducing body weight or fat mass.
Garcinia has no generally recognized therapeutic dosage, as its therapeutic value has not been established. Dieters commonly take 500 to 700 mg 1/2 hour before meals. Garcinia has been consumed in foods for centuries, and appears to be safe at several times this dosage range.