Garcinia Cambogia: What the Weight-Loss and Liver Evidence Shows

Garcinia cambogia does not produce meaningful weight loss. In the largest and best-run trial, published in JAMA in 1998, people taking its active ingredient, hydroxycitric acid, lost 3.2 kg in 12 weeks; people on placebo lost 4.1 kg.^[1] Pooled analyses of the smaller trials find an average edge of about 0.9 to 1.3 kg,^[2][3] and in the review that tested it, the edge disappeared when the weakest studies were set aside.^[2] Against that sits a documented, if uncommon, risk of serious liver injury, including liver failure, transplants and deaths.^[12][13][14] No study has tested garcinia with a GLP-1 drug, and the one human study that measured GLP-1 after hydroxycitric acid found no change.^[8]

What garcinia cambogia is

Garcinia cambogia, now classified botanically as Garcinia gummi-gutta and also called Malabar tamarind or brindleberry, is a tree from India and Southeast Asia. The rind of its small pumpkin-shaped fruit has long been used to sour and preserve food.^[11][12] Supplements are extracts of that rind, standardized, at least on the label, to a percentage of hydroxycitric acid (HCA).

The weight-loss theory comes from biochemistry. HCA blocks an enzyme called ATP citrate lyase, which cells use in an early step of turning surplus carbohydrate into fat.^[1] In rodents, HCA reduced body weight and food intake.^[7] Marketing adds a second promise, that it curbs appetite. Both ideas have been tested in people.

The 1998 JAMA trial: no difference from placebo

The trial that settled the question for many obesity researchers ran at Columbia University’s obesity research center. It randomized 135 adults with an average BMI of about 32 to 1,500 mg of HCA a day or a matching placebo for 12 weeks. Both groups followed the same high-fiber, low-calorie diet.^[1]

• Weight. The HCA group lost an average of 3.2 kg and the placebo group 4.1 kg. The difference, which slightly favored placebo, was not statistically significant (p = 0.14).^[1]
• Body fat. HCA did not change the share of weight lost as fat or the amount of fat lost.^[1]
• Dropouts. About six in ten people in each group finished, 64% on HCA and 61% on placebo.^[1]
• Side effects. Gastrointestinal complaints were about twice as common on HCA as on placebo.^[2]

The authors’ conclusion was flat: garcinia “failed to produce significant weight loss and fat mass loss beyond that observed with placebo.”^[1] A meta-analysis later rated it the largest and most rigorous trial in the field.^[2]

What the meta-analyses found

Most other garcinia trials are smaller, shorter and less carefully reported. When reviewers pool them, they find a small average benefit that shrinks or vanishes depending on which trials are allowed in.

The 2011 Exeter review is the one most often quoted. Its pooled 0.88 kg was borderline, with a confidence interval that ran right up to zero. Three small trials drove the result, and when they were excluded, garcinia was no longer better than placebo. The authors judged the effect “no longer statistically significant when only rigorous RCTs are considered” and its clinical relevance questionable.^[2] The 2020 review that found a significant 1.34 kg pooled only eight trials, again mostly small and short.^[3] A 2020 analysis of herbal weight-loss trials set 2.5 kg as the smallest difference that matters clinically, and garcinia did not reach significance at all.^[4]

For scale, the most favorable estimate is about a kilogram and a third over two to three months, in trials that nearly always paired the capsule with a calorie-cut diet. For comparison with prescription drugs, our review of GLP-1 supplements shows how far supplement effects fall short of semaglutide and tirzepatide, and the supplement evidence grader scores garcinia beside 15 other products.

Does garcinia curb appetite or burn fat?

The appetite claim has been tested directly, with mixed results that lean negative:

• Appetite over 12 weeks. In 89 women with mild overweight on a low-calorie diet, those taking 1.2 g of HCA a day lost more weight than those on placebo, 3.7 against 2.4 kg. But HCA had no effect on hunger, fullness or food intake, and the authors concluded the study “does not support a satiety effect of HCA.”^[5]
• Food intake in a lab. In a two-week crossover of 24 adults given HCA in tomato juice, energy intake over 24 hours fell 15% to 30% against placebo. The study was single-blind and small.^[6]
• Fat burning. In 10 men given 3 g of HCA a day for three days, energy expenditure and the body’s balance of fat and carbohydrate burning did not change, at rest or during exercise.^[7]

So the enzyme effect seen in animals has not shown up as more fat burned in people, and the appetite effect appeared in one small lab study but not in a 12-week trial that measured it.

Garcinia and GLP-1: one study, no effect

Whether HCA acts on GLP-1, the gut hormone that drugs like semaglutide mimic, has been tested in people once. Researchers in Adelaide infused 2,800 mg of HCA directly into the small intestine of 12 healthy adults and 8 people with type 2 diabetes, then gave a glucose infusion. In the healthy volunteers, HCA lowered blood sugar slightly and raised a different gut hormone, GIP, but caused no change in GLP-1 or insulin. In the people with diabetes, it had no effect on blood sugar or GLP-1.^[8]

No trial has tested garcinia in people taking semaglutide, tirzepatide or another GLP-1 drug, either for added weight loss or for safety. The GLP-1 supplements review covers the products sold on that claim. On the liver point below, anyone on a GLP-1 who has abnormal liver tests should tell the prescriber about every supplement; our page on GLP-1 drugs and liver enzymes explains what those tests usually mean.

Garcinia and liver injury

The NIH’s LiverTox database, which clinicians use to judge whether a product can damage the liver, states that weight-loss products labeled as containing garcinia have been “linked to the development of clinically apparent acute liver injury which can be severe and even fatal.”^[12] The strongest evidence comes from the Drug-Induced Liver Injury Network, a federally funded registry that adjudicates each case with expert panels.

• The network’s cases. Of 1,418 patients enrolled from 2004 to 2018, 22 had liver injury attributed with high confidence to garcinia, five from garcinia alone and most of the rest from products that also contained green tea extract. Patients were 17 to 54 years old. Injury appeared a median of 51 days after starting. Ninety-one percent were hospitalized, one needed a transplant and one died.^[13]
• A genetic clue. 55% of the garcinia cases carried the immune gene variant HLA-B*35:01, against 19% of people injured by other supplements and 12% of people injured by prescription drugs. That pattern suggests an immune reaction in susceptible people rather than a straight dose effect.^[13]
• The wider record. A 2025 review counted more than 200 reports of liver injury in adverse-event databases and 34 published case reports, including one death and nine liver transplants. In one case, the injury came back when the person took garcinia again, which is the strongest kind of evidence for cause in a single patient. The review says these reports led the US Pharmacopeia to add a liver-damage caution to its garcinia ingredient standards.^[14]
• Individual cases. Published reports include a patient who needed a liver transplant for fulminant liver failure,^[15] and four women in Italy with acute liver failure after taking garcinia extract for weight loss.^[16]

Two things keep this in proportion. First, injury is uncommon; the NIH’s complementary-medicine center says severe cases appear to be uncommon, and lists headache, nausea and diarrhea among the other side effects.^[11] Second, many cases involve multi-ingredient products, so garcinia is not always the only suspect. Even so, a national survey estimated that 15.6 million US adults had used at least one of six botanicals with known liver risk, garcinia among them, in the previous month.^[17] A supplement that adds little more than a kilogram at best does not have much benefit to set against a rare risk of liver failure.

These symptoms come from FDA’s own list.^[18] Anyone who develops them while taking garcinia or any weight-loss supplement should stop it and get liver blood tests promptly.

The Hydroxycut recall of 2009

Garcinia’s liver reputation is tied to Hydroxycut, a best-selling line of weight-loss supplements. Versions containing ephedra had already been withdrawn in 2004 because of heart risks.^[20] On May 1, 2009, FDA told consumers to stop using Hydroxycut products immediately. The agency had received 23 reports of serious health problems, from jaundice to liver damage that required a transplant, and one death from liver failure. The manufacturer agreed to recall 14 products.^[18]

“The agency has not yet determined which ingredients, dosages, or other health-related factors may be associated with risks related to these Hydroxycut products. The products contain a variety of ingredients and herbal extracts.”

— FDA news release, May 1, 2009

That uncertainty never fully cleared. A case series of 17 Hydroxycut liver injuries, three of which led to transplants and one to death, concluded that the product was “clearly implicated” in severe liver injury but that the specific responsible ingredient remained uncertain. The authors listed garcinia cambogia among the ingredients of concern, alongside cissus, caffeine and green tea extract.^[19] The 2011 Exeter review described Hydroxycut as an HCA-containing slimming pill.^[2] Hydroxycut products with different formulas returned to the market, and LiverTox notes that newer versions have continued to be implicated in liver injury.^[20] Garcinia was in the frame in 2009 but was never singled out as the cause; the case against garcinia itself rests on the later registry data above.

Mania and serotonin reactions

A smaller set of case reports links garcinia to psychiatric reactions. A case report described serotonin toxicity in a person taking an over-the-counter garcinia supplement,^[21] and a systematic review of herbal-associated mania found four reports involving garcinia (listed as brindleberry) and one involving Hydroxycut. That review cautioned that cause is hard to assign, in part because several patients were also taking antidepressants.^[22] NCCIH notes that interactions between garcinia and some drugs affecting serotonin have been reported.^[11] People taking an SSRI or another serotonin-active drug have one more reason to skip it.

What is in the bottle

Garcinia is sold as a dietary supplement, which means FDA does not approve it before sale and the maker is responsible for its safety and labeling.^[11] Dose varies widely. When researchers in Norway and India measured HCA in ten garcinia supplements, content ranged from 29 mg to 289 mg per capsule or tablet, a tenfold spread.^[10] The 1998 JAMA trial used 1,500 mg of HCA a day,^[1] so what a given bottle delivers relative to the studies is often unclear.

How garcinia was sold, and what the FTC did

The Federal Trade Commission has brought at least two cases against garcinia sellers, part of the same enforcement wave that hit raspberry ketone marketers:

• Sale Slash, 2016. The FTC said the company sold “Pure Garcinia Cambogia” and other diet pills using spam email, fake news sites and phony celebrity endorsements. The settlement imposed a partially suspended $43.4 million judgment, with about $10 million to be collected, most of it for refunds.^[24]
• Cure Encapsulations, 2019. In what the FTC called its first case over fake paid reviews on an independent retail website, a garcinia seller had claimed on Amazon that its capsules were a powerful appetite suppressant that “Literally BLOCKS FAT From Forming” and caused weight loss of up to twenty pounds, backed by reviews it paid a third party to write. The order bars such claims unless supported by human clinical testing.^[25]

Those claims sit badly against the trial record. Fat blocking was the enzyme theory that the JAMA trial and the fat-burning study failed to confirm in people,^[1][7] and no controlled trial has produced anything near twenty pounds. For enforcement against sellers of GLP-1 products, see our FDA warning letter register.

The bottom line

Garcinia cambogia has been studied for more than 25 years. The best trial found it no better than placebo, pooled analyses find at most about a kilogram and a third over a few months, and independent reviews call the evidence too weak to recommend it or inconclusive at best.^{[1][2][4][23]} Its main documented harm, liver injury, is rare but can be fatal. For a different supplement with an equally thin record, see the capsaicin and capsinoids review. For people with obesity who want a treatment that works, prescription options with real trial data are the place to start, and a clinician can say whether one fits.