Extracted from the dehydrated fruit rind of
G. cambogia, hydroxycitric acid is one such dietary supplement, which is a popular cooking ingredient in Southern India. Its mechanism of action consists of preventing the activity of the ATP-dependent citrate lyase enzyme, which stimulates the breakdown of citrate into oxaloacetate and acetyl-CoA, thus either inducing a sense of satiety or lessening the appetite (
21,
22). Consumed for centuries on a regular or supplemental basis,
G. cambogia is claimed to be free of adverse or side effects (
22). Experiments on rats and humans indicate that administering hydroxycitric acid indeed contributes to a feeling of satiety and subsequent weight reduction (
23). Conversely, a number of human trials have produced unconvincing evidence, supporting that no significant difference was found between the effects of this supplement and those of the placebo (
24-
27). The results of a meta-analysis, which pooled the data from nine clinical trials, evaluating the effectiveness of hydroxycitric acid in weight reduction, indicated that hydroxycitric acid is relatively more effective than the placebo (mean difference: - 0.88 kg; 95% confidence interval (CI): 0.00-1.75 kg). Collectively, research trials point to the fact that
G. cambogia extracts can positively act as weight loss agents, on a short-term basis. Nonetheless, their effect is limited and their clinical relevance is yet to be determined (
28). In conclusion, given the fact that most human trials have been conducted on a short-term basis and on small patient samples, there is no proof supporting the effectiveness of
G. cambogia for a length of time longer than 12 weeks of administration.