How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Garcinia cambogia
A fruit from South-East Asia, the extract of which – hydroxycitric acid – is a best-seller amongst slimming supplements. The results of clinical trials are frankly contradictory, and rare cases of serious liver damage have been reported.
Benefits
- Resulted in 0.88 kg greater weight loss than the placebo across 12 randomised trials — a difference whose clinical significance the authors themselves consider to be uncertain
- Reduces visceral, subcutaneous and total body fat when taken at a dose of 1,000 mg per day for 12 weeks (44 participants), with no rebound effect upon discontinuation
- Reduced the visceral adiposity index in 99 obese men to 166 mg per day over three months
- When combined with Amorphophallus konjac, it lowered total cholesterol and LDL levels in 58 obese people — whilst their weight remained unchanged
Precautions
Cases of liver damage have been reported: four cases of acute liver injury in women taking the drug to lose weight, and two cases of liver failure leading to a transplant. These cases remain rare given the widespread use of the product, and clinical trials have not identified any significant toxicity — but they are sufficient to ensure it is not taken lightly, particularly if you have a compromised liver or are taking other medicines. The hydroxycitric acid it contains is also found in slimming supplements that have been banned due to hepatotoxicity. Digestive problems were twice as common as with the placebo in one trial. It is also worth noting that the results vary from one trial to another. The largest trial — involving 135 overweight adults, 1,500 mg of hydroxycitric acid, over 12 weeks — found no greater weight or fat loss than with the placebo; another trial, involving 86 people taking 2 g per day for 10 weeks, also found no effect. A 2012 review summarises the situation: limited evidence, based on small sample sizes and short study durations.
Recommended dosage
The trials range from 166 mg to 2 g of extract per day, or 1,500 mg of hydroxycitric acid. No particular dose stands out as being effective: the largest trial, which used precisely 1,500 mg of hydroxycitric acid, found no benefit.
How to take it
- Tested doses: from 166 mg to 2 g of extract per day, or 1,500 mg of hydroxycitric acid, for 8 to 12 weeks.
- No dose stands out: the largest trial (135 adults, 1,500 mg of hydroxycitric acid for 12 weeks) did no better than placebo.
- What to expect: 0.88 kg more than placebo in the meta-analysis of 12 trials, a difference whose relevance remains uncertain.
Did you know?
Although popular for weight loss, Garcinia cambogia has been linked to rare but serious cases of acute liver failure, sometimes requiring a liver transplant.
What the studies say
This systematic review and meta-analysis of twelve randomized clinical trials examined the efficacy of Garcinia extract (HCA) as an aid to weight loss. The results revealed a small, statistically significant difference in favor of HCA compared to placebo (-0.88 kg of weight loss). However, the clinical relevance of this effect is uncertain, and gastrointestinal adverse events were twice as frequent with HCA in one study.
Onakpoya I, Hung SK, Perry R, Wider B, Ernst E. — Journal of obesity (2011) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more