Garcinia Cambogia (Malabar Tamarind) is a small fruit that has some traditional usage to improve the culinary experience of dinner, but beyond that has limited medical use. It is an excellent source of hydroxycitric acids (structurally associated with citric acid, a sour flavorant) and one of the isomers, known as (-)-Hydroxycitric acid, is thought to aid in weight-control.
The device of action is curbing an enzyme called Citric lysase that will be needed in fatty acids' synthesis, known as de novo lipogenesis.
Some separated reports do notice fat loss, however it seems to be unreliable and quite varied. Many reports also do document subjective hunger decrease, but tend to document dropout rates (how often people abandon the research on account of being unable to maintain the diet method) in place of diet; actually then the gains remain unreliable and often not present.
After doing even more website research I found a forum that hands out a trustworthy analysis on these successful garcinia supplements:
Though there's some restricted potential for (-)-Hydroxycitric acid as a fat loss aid, the scale of effect is very low (around 2kg more than 3 months) and the benefit is unreliable; making it hard to advocate this ingredient as a fatburner or anti-obesity agent.