Garcinia

Garcinia cambogia is a tropical fruit; supplements use rind extracts standardized to hydroxycitric acid (HCA). Marketed aggressively for weight loss based on a proposed ATP-citrate lyase inhibition mechanism and possible serotonergic appetite effects. The clinical evidence does not support the marketing: Onakpoya et al., 2011 meta-analysis of 12 RCTs (n=706) found a statistically significant but clinically trivial difference of −0.88 kg vs placebo, with the authors concluding 'the magnitude of the effect is small, and the clinical relevance is uncertain.' Heymsfield et al., 1998 JAMA RCT (n=135) was outright null on body weight and fat mass. The more important issue is safety: multiple peer-reviewed case reports document acute hepatitis and hepatic failure (including transplant cases) attributed to garcinia-containing products (Crescioli 2018, Lunsford 2016, Kothadia 2018). LiverTox classifies garcinia cambogia as a Likelihood Category B cause of drug-induced liver injury, with ~200 documented adverse events including one death and nine liver transplants. The FDA issued safety communications on Hydroxycut formulations that contained garcinia; causality is complicated by contamination and multi-ingredient formulas, but the signal is real enough that pure garcinia products warrant a hepatotoxicity warning. Drug-interaction caveats: HCA may lower blood glucose — diabetics taking insulin, metformin, sulfonylureas, or GLP-1 agonists should monitor for hypoglycemia. Insufficient safety data in pregnancy and lactation; avoid during these periods.

Limited clinical evidence. Onakpoya 2011 meta-analysis (12 RCTs, n=706): −0.88 kg vs placebo, clinical relevance uncertain per authors. Heymsfield 1998 JAMA RCT (n=135): null on weight and fat mass. Multiple hepatotoxicity case reports including transplant cases — listed in LiverTox.