So… unfortunately, the weight loss effects appear to be both weak and inconsistent. A review published in the Journal of Obesity in 2011 that looked at 12 clinical trials found that Garcinia Cambogia can increase weight loss by about 0. 88 kg, or 2 pounds, on average, over a period of several weeks (13). Their conclusion sums it up quite nicely: …Garcinia extractsHCA can cause short-term weight loss. The magnitude of the effect is small, and the clinical relevance is uncertain.