Garcinia Cambogia

What is Garcinia cambogia?

Garcinia cambogia, now classified as Garcinia gummi-gutta, is a tree native to India and Southeast Asia, also called Malabar tamarind or brindle berry. Its sour fruit rind is used in cooking, especially in fish curries, and as a food preservative (NCCIH: Garcinia Cambogia).

The rind contains hydroxycitric acid (HCA), typically 10% to 30% by weight. HCA inhibits ATP citrate lyase, an enzyme involved in making fatty acids, which is the basis for claims that garcinia “blocks fat production.” Supplement extracts often contain 20% to 60% HCA (LiverTox: Garcinia Cambogia).

What the research says

Weight loss

The best-known trial, published in JAMA, randomized 135 adults with overweight to 1,500 mg of HCA a day or placebo for 12 weeks, alongside a low-calorie, high-fiber diet. Both groups lost weight, but there was no significant difference between them (3.2 kg with garcinia versus 4.1 kg with placebo), and fat loss was similar (Heymsfield et al., 1998).

A systematic review and meta-analysis of randomized trials found a small, statistically significant extra weight loss with HCA of about 0.9 kg compared with placebo. The authors described the effect as small and of uncertain clinical relevance, and they noted that gastrointestinal side effects were about twice as common with HCA in one study (Onakpoya et al., 2011). NCCIH summarizes the evidence by saying it is unclear whether garcinia helps with weight loss (NCCIH: Garcinia Cambogia).

Liver safety

LiverTox rates garcinia a “likely rare cause of clinically apparent liver injury.” It describes at least a dozen cases in people taking multi-ingredient products containing garcinia and more recent cases with products labeled as garcinia alone. Symptoms such as fatigue, nausea and jaundice usually appeared 1 to 4 weeks after starting, and some cases led to acute liver failure, transplant or death. The estimated frequency is less than 1 in 10,000 users. Rare reports of serotonin syndrome and muscle breakdown have also been described (LiverTox: Garcinia Cambogia).

How it’s used in supplements

Garcinia appears in capsules, gummies, teas and multi-ingredient “fat burner” blends, often standardized to 50% or 60% HCA. Trials have commonly used around 1,500 mg of HCA a day, split before meals. Teas and blends rarely say how much HCA they provide.

Other reported side effects include headache, nausea and diarrhea. NCCIH notes reported interactions with some drugs affecting the liver and some drugs affecting serotonin, such as certain antidepressants, and says little is known about safety in pregnancy or breastfeeding (NCCIH: Garcinia Cambogia). Stop using it and contact a doctor if you notice yellowing skin or eyes, dark urine, unusual fatigue or abdominal pain. People with liver disease or who drink heavily should avoid it.