Garcinia cambogia contains an organic acid named hydroxycitrate (HCA) which is said to be responsible for many of the properties of the plant. HCA is capable of changing the body's calorie metabolism from storing fat till increasing the production of glycogen (depoted sugar) in stead.
For use in diets, the effect is increased if supplemented with especially chromium and conjugated linoleic acid (CLA).
There have been no reports of toxic effects when using Garcinia cambogia.
Also see "Diet Products".