Garcinia cambogia (now classified botanically as Garcinia gummi-gutta, and also called Malabar tamarind) is a tropical fruit from South and Southeast Asia. The dried rind is used in cooking and as a food preservative. Extracts of the rind are sold as weight-loss supplements because they contain (−)-hydroxycitric acid (HCA), a molecule that blocks a fat-making enzyme in laboratory and animal studies.
The human evidence is weak. The largest early randomized trial, published in JAMA in 1998, found no extra weight or fat loss compared with placebo. Meta-analyses since then report, at most, about 1 kg more weight loss than placebo over a few months, which their authors describe as small and of uncertain clinical value. Meanwhile, products containing Garcinia have been linked to rare but serious liver injury, including liver failure, and to case reports of mania and serotonin toxicity.
This page summarizes what clinical trials, meta-analyses, liver-injury registries and US regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Type | Botanical extract; sold as a dietary supplement in the US |
| Source | Dried fruit rind (pericarp) of Garcinia gummi-gutta (syn. G. cambogia) |
| Main active ingredient | (−)-Hydroxycitric acid, C₆H₈O₈, 208.12 g/mol (PubChem) |
| Claimed mechanism | Competitive inhibition of ATP citrate lyase, an enzyme needed to make fat from carbohydrate (shown in lab and animal studies) |
| Doses in trials | About 1–2.8 g HCA per day in the trials pooled by Onakpoya et al.; 1.5 g/day in the 1998 JAMA trial |
| Half-life | Not established in humans; only small absorption studies exist |
| Weight effect | −0.88 kg vs placebo in a 2011 meta-analysis; not significant in the best-quality trials |
| Main risk | Rare, sometimes severe acute liver injury; case reports of mania and serotonin toxicity |
| US status | Unapproved for any disease; FDA does not review supplements for safety or efficacy before sale |
| WADA | Not named on the 2026 Prohibited List |
What it is
The fruit rind contains HCA at roughly 30% by weight, but free HCA readily converts to an inactive ring-shaped form called a lactone (van Breemen et al., Pharm Biol 2025). Commercial extracts therefore usually add calcium, sodium or potassium to form a hydroxycitrate salt that stays in the active form. The US Pharmacopeia defines Garcinia as the dried pericarp containing at least 12% HCA plus its lactone.
The ATP citrate lyase theory
ATP citrate lyase is an enzyme in the cell’s cytoplasm (outside the mitochondria) that splits citrate into acetyl-CoA, the raw material for building fatty acids and cholesterol. HCA is a competitive inhibitor of this enzyme (Heymsfield et al., JAMA 1998). The weight-loss idea is that blocking it should reduce de novo lipogenesis, the conversion of excess carbohydrate into fat.
The supporting data come from laboratory and animal work:
- In isolated rat liver cells, HCA reduced the synthesis of triglycerides, phospholipids, cholesterol and free fatty acids (Hamilton et al., Lipids 1977).
- In rats, oral HCA suppressed liver fatty acid and cholesterol synthesis and lowered blood triglycerides in several models of high blood lipids (same study).
- In isolated rat brain cortex, HCA increased the release of serotonin, a finding sometimes used to explain claimed appetite effects (Ohia et al., Res Commun Mol Pathol Pharmacol 2001).
These effects have not translated clearly to people. When HCA was tested directly in humans, it did not change fat burning (see below).
How it works in the body
Human pharmacokinetic data are sparse:
| Study | What was measured | Finding |
|---|---|---|
| Loe et al., Anal Biochem 2001 | Plasma HCA in 4 people after a single 2 g dose | 0.8 µg/mL at 30 min and 8.4 µg/mL at 2 h; absorbed, but present in small amounts |
| van Loon et al., Am J Clin Nutr 2000 | Plasma HCA and fuel use in 10 trained cyclists given a large HCA drink | Plasma HCA rose to 0.39 mmol/L (82 mg/L), but total fat and carbohydrate oxidation did not differ from placebo at rest or during 2 h of exercise |
No elimination half-life for HCA in humans was reported in the sources we reviewed, so none is given here.
Regulatory status
In the US, Garcinia cambogia and HCA are sold as dietary supplements. They are not approved drugs for obesity or any other condition, and supplements do not need FDA approval before they are marketed (Fong et al., Am J Gastroenterol 2010).
In 2024, the US Pharmacopeia’s expert committees recommended a cautionary labeling statement about potential liver toxicity and revised the USP Garcinia ingredient monographs to include it (van Breemen et al., Pharm Biol 2025). USP monographs are quality standards, not FDA rules.
Neither Garcinia nor HCA is named on the WADA 2026 Prohibited List.
What the research shows
The 1998 JAMA trial: no benefit over placebo
The most cited trial is a 12-week, randomized, double-blind, placebo-controlled study of 135 overweight adults with a mean BMI of about 32 kg/m² (Heymsfield et al., JAMA 1998). Both groups followed a high-fiber, low-energy diet. The active group took Garcinia cambogia providing 1,500 mg HCA per day.
| Outcome | HCA (n = 66) | Placebo (n = 69) |
|---|---|---|
| Completed 12 weeks | 42 (64%) | 42 (61%) |
| Mean weight loss (SD) | 3.2 kg (3.3) | 4.1 kg (3.9) |
| Between-group difference | Not significant (p = 0.14) | — |
| Body fat loss | No significant difference | — |
The authors concluded that Garcinia cambogia “failed to produce significant weight loss and fat mass loss beyond that observed with placebo.” Later reviewers have argued that the high-fiber diet or the calcium salt used may have reduced HCA absorption (Andueza et al., Nutrients 2021). That is a hypothesis; it has not been tested in a trial designed to answer it.
Meta-analyses
| Review | Trials included | Result vs placebo |
|---|---|---|
| Onakpoya et al., J Obes 2011 | 12 RCTs (706 people); 9 pooled | Weight −0.88 kg (95% CI −1.75 to −0.00), about 1% of body weight. Not significant when only the two best-quality trials were pooled (MD +0.88 kg, 95% CI −0.33 to 2.10). BMI change not significant. |
| Golzarand et al., Complement Ther Med 2020 | 8 RCTs (530 people) | Weight −1.34 kg (95% CI −2.62 to −0.07); BMI −0.99 kg/m²; body fat −0.42 percentage points; waist −4.16 cm |
| Maunder et al., Diabetes Obes Metab 2020 | 54 herbal-medicine RCTs overall | No effect on weight for Garcinia cambogia as a single agent; a difference of 2.5 kg or more was required to count as clinically meaningful |
Onakpoya and colleagues noted that every included trial had methodological weaknesses, that three small trials drove the positive overall result, and that the largest and most rigorous trial found no difference. HCA doses in the pooled trials ranged from 1 to 2.8 g per day. They concluded the effect is small and its clinical relevance uncertain.
For comparison, the same authors cited a meta-analysis in which the prescription drug orlistat produced about 2.9 kg more weight loss than placebo.
Appetite and fat burning
Direct tests of the proposed mechanisms in people have been negative:
- Fat oxidation. In trained cyclists, a large HCA dose raised plasma HCA but did not increase fat burning at rest or during exercise (van Loon et al., Am J Clin Nutr 2000).
- Blood sugar and liver enzymes. A 2025 meta-analysis of 9 trials (444 people) found no significant effect on fasting glucose, insulin, ALT or AST (Tavakoli et al., J Nutr Sci 2025).
Side effects and risks
In short trials, reported side effects were mostly minor: headache, rash, colds and gastrointestinal complaints. In one trial, gastrointestinal adverse events were twice as common with HCA as with placebo (Onakpoya et al., J Obes 2011). Trials are too small and too short to detect rare reactions. The serious problems below come from case reports and liver-injury registries.
The Hydroxycut recall (2009)
On May 1, 2009, the FDA told consumers to stop using Hydroxycut products made by Iovate Health Sciences, and Iovate agreed to recall them (FDA, 2009). The details matter:
- What FDA had received: 23 reports of serious health problems, from jaundice and raised liver enzymes to liver damage requiring transplant, plus one death from liver failure. Other reports included seizures, cardiovascular disorders and rhabdomyolysis (muscle breakdown).
- Which products: 14 listed products, including Hydroxycut Regular, Caffeine-Free, Hardcore and Max caplets, drink packets and ready-to-drink products, Hydroxycut 24, Carb Control and Natural. Hydroxycut Cleanse and Hoodia products were not part of the recall.
- Which ingredient: FDA said it had “not yet determined which ingredients” were responsible. The products contained a variety of ingredients and herbal extracts.
So the FDA warning was about multi-ingredient Hydroxycut products, not a finding that Garcinia itself caused the injuries. Hepatologists noted that the formulations of the time, after ephedra (ma huang) had been removed, still contained ingredients of concern including Garcinia cambogia, Cissus quadrangularis, caffeine and green tea extract (Fong et al., Am J Gastroenterol 2010). One review reported that only 8 of the 14 products sold under the Hydroxycut name contained Garcinia cambogia (Andueza et al., Nutrients 2021).
LiverTox, the NIH drug-induced liver injury database, summarizes the history: Hydroxycut products containing ephedra were withdrawn in 2004 because of cardiovascular risks, and products were withdrawn again in 2009 because of liver toxicity. Reformulated products with different ingredients have continued to be implicated in liver injury (LiverTox: Hydroxycut). For the ephedra history, see ephedrine.
The Hydroxycut case series
Fong and colleagues, including an FDA reviewer, assessed 17 cases of liver injury after Hydroxycut: 8 seen at US academic centers between 2002 and 2009, and 9 from FDA MedWatch reports with enough clinical detail (Fong et al., Am J Gastroenterol 2010).
| Finding | Result |
|---|---|
| Hospitalized | All 17 |
| Liver transplant | 3 of the 8 academic-center patients |
| Deaths | 1 (acute liver failure, FDA case) |
| Time to symptoms (academic-center patients) | 1–8 weeks, median 6 weeks (2 long-term outliers) |
| Peak ALT (academic-center patients) | 1,450–5,396 U/L |
| Causality rating | 8 definite, 5 highly likely, 2 probable, 2 possible |
As far as the authors could tell, all 17 patients took the doses suggested by the manufacturer. They wrote that the specific ingredient responsible remained uncertain.
Liver injury from Garcinia-containing products
LiverTox states that weight-loss products labeled as containing Garcinia cambogia have been linked to clinically apparent acute liver injury that can be severe and even fatal (LiverTox: Garcinia Cambogia).
The most detailed data come from the US Drug-Induced Liver Injury Network (DILIN), which prospectively enrolls and adjudicates suspected cases (Vuppalanchi et al., Clin Gastroenterol Hepatol 2022). Among cases enrolled from 2004 to 2018, it identified 22 high-confidence cases from products containing Garcinia cambogia: 5 with Garcinia alone, 16 with Garcinia plus green tea, and 1 with Garcinia plus ashwagandha.
| Feature | Garcinia-containing products (n = 22) |
|---|---|
| Age | 17–54 years (median 35); 55% women |
| Reason for use | Weight loss in 82% |
| Time from starting to injury | 13–223 days (median 51) |
| Pattern | Hepatocellular (liver-cell) injury with jaundice |
| Peak aminotransferases | 2,001 ± 1,386 U/L, higher than control groups |
| Hospitalized | 91% |
| Severe or fatal | 1 death, 1 liver transplant |
| HLA-B*35:01 gene variant | 55%, vs 19% with other supplements and 12% with conventional drugs |
Key points from the study:
- Garcinia alone can cause it. In one case, chemical analysis confirmed Garcinia in a product whose label listed no green tea. In another, a product labeled as containing both Garcinia and green tea contained Garcinia but no detectable green tea catechins.
- It looks the same as green tea injury. The authors described the liver injury from Garcinia and from green tea as clinically indistinguishable. See green tea extract for that ingredient’s liver-safety record.
- An immune mechanism is suspected. The link with HLA-B*35:01, an immune-system gene variant also tied to green tea liver injury, suggests an immune-mediated reaction in susceptible people.
- Labels were unreliable. Product contents often did not match the label.
A 2025 review of the case reports that prompted the USP labeling change found more than 200 reports of liver adverse events linked to Garcinia in adverse-event databases and 34 published case reports, with one death and nine liver transplants (van Breemen et al., Pharm Biol 2025). In one case, the injury recurred when Garcinia was taken again, which supports causation.
How many people are exposed? A nationally representative US survey (NHANES 2017–2020) found Garcinia cambogia among six botanicals flagged for liver risk; 20 of 9,685 adult participants reported using a Garcinia product in the past 30 days (Likhitsup et al., JAMA Netw Open 2024). Because use is fairly common and injury is rare, the absolute risk per user is unknown.
Serotonin toxicity and mania
Case reports describe psychiatric and serotonin-related reactions. A causal link has not been established:
- Serotonin toxicity. A 35-year-old woman who had taken escitalopram (an SSRI antidepressant) for a year developed stuttering speech, clonus (rhythmic involuntary muscle jerks), sweating, high blood pressure, fast heart rate and overactive reflexes after 2–3 months of a Garcinia cambogia product (60% HCA, with chromium, potassium and calcium) (Lopez et al., J Med Toxicol 2014; details as tabulated by Andueza et al., Nutrients 2021).
- Mania. A New York case series described three adults who developed mania or hypomania after 1–2 months of Garcinia cambogia; two had a history of bipolar disorder and one did not (Hendrickson et al., Prim Care Companion CNS Disord 2016; details as tabulated by Andueza et al.). Two further single cases have been published, one in a woman with bipolar disorder taking paroxetine, an SSRI.
The serotonin explanation rests largely on the rat brain-tissue data above. Reviewers note that several patients had psychiatric histories or were on antidepressants, so the evidence is limited (Andueza et al., Nutrients 2021).
Groups flagged in the literature
The sources above single out:
- people taking SSRIs, given the serotonin toxicity case;
- people with bipolar disorder or a history of hypomania, given the mania case reports;
- pregnant and breastfeeding women, for whom reviewers say use should be discouraged (Andueza et al., Nutrients 2021).
Marketing and FTC actions
The Federal Trade Commission has brought cases over how Garcinia products were advertised:
- Tarr, Inc. (2017). The FTC settled with a network of online marketers that sold more than 40 weight-loss, muscle and anti-wrinkle products, using fake news sites and celebrity endorsements the celebrities never gave. An ad for “Miracle Garcinia Cambogia” claimed a user lost 23 lbs in 5 weeks without special diet or exercise. The order imposed a $179 million judgment, suspended after payment of about $6.4 million (FTC, 2017).
- Cure Encapsulations (2019). In its first case challenging fake paid reviews on an independent retail website, the FTC alleged that the seller of a Garcinia cambogia extract on Amazon claimed without support that it was a “powerful appetite suppressant” that blocks fat and causes weight loss of up to 20 pounds, and paid a website to post fabricated five-star reviews. The order bars weight-loss claims without human clinical testing and imposed a $12.8 million judgment, suspended upon payment of $50,000 and certain unpaid taxes (FTC, 2019).
Key takeaways
- The mechanism is real in the lab, not in practice. HCA inhibits ATP citrate lyase in liver cells and rats, but in humans it did not increase fat burning.
- Weight loss is small or absent. The 1998 JAMA RCT found no benefit over placebo, and meta-analyses report about 1 kg at most, which disappears when only the best trials are pooled.
- The 2009 FDA warning covered Hydroxycut products, not Garcinia alone. FDA never identified the responsible ingredient in those multi-ingredient products.
- Garcinia itself is now linked to liver injury. NIH’s DILIN network documented cases from Garcinia-only products, with 91% hospitalized and one death and one transplant among 22 cases.
- Psychiatric reactions are reported but unproven. Case reports describe serotonin toxicity in a patient on an SSRI and mania, often in people with bipolar disorder.
- Marketing has outpaced the evidence. The FTC has acted against Garcinia sellers for unsupported weight-loss claims, fake endorsements and fake reviews.
Sources
- Heymsfield SB, Allison DB, Vasselli JR, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA. 1998;280(18):1596–1600. PubMed.
- Onakpoya I, Hung SK, Perry R, et al. The use of Garcinia extract (hydroxycitric acid) as a weight loss supplement: a systematic review and meta-analysis of randomised clinical trials. J Obes. 2011;2011:509038. PubMed.
- Golzarand M, Omidian M, Toolabi K. Effect of Garcinia cambogia supplement on obesity indices: a systematic review and dose-response meta-analysis. Complement Ther Med. 2020;52:102451. PubMed.
- Maunder A, Bessell E, Lauche R, et al. Effectiveness of herbal medicines for weight loss: a systematic review and meta-analysis of randomized controlled trials. Diabetes Obes Metab. 2020;22(6):891–903. PubMed.
- Tavakoli S, Amini MR, Rabiee R, et al. The effects of Garcinia cambogia on glycaemic control and liver enzymes in adults: a systematic review and meta-analysis of randomised controlled trials. J Nutr Sci. 2025;14:e8. PubMed.
- van Loon LJ, van Rooijen JJ, Niesen B, et al. Effects of acute (-)-hydroxycitrate supplementation on substrate metabolism at rest and during exercise in humans. Am J Clin Nutr. 2000;72(6):1445–1450. PubMed.
- Loe YC, Bergeron N, Rodriguez N, Schwarz JM. Gas chromatography/mass spectrometry method to quantify blood hydroxycitrate concentration. Anal Biochem. 2001;292(1):148–154. PubMed.
- Ohia SE, Awe SO, LeDay AM, et al. Effect of hydroxycitric acid on serotonin release from isolated rat brain cortex. Res Commun Mol Pathol Pharmacol. 2001;109(3-4):210–216. PubMed.
- Hamilton JG, Sullivan AC, Kritchevsky D. Hupolipidemic activity of (–)-hydroxycitrate [sic]. Lipids. 1977;12(1):1–9. PubMed.
- National Center for Biotechnology Information. Garcinia acid (CID 185620). PubChem. PubChem.
- Food and Drug Administration. FDA warns consumers to stop using Hydroxycut products: dietary supplements linked to one death; pose risk of liver injury. News release, May 1, 2009. FDA (archived).
- Fong TL, Klontz KC, Canas-Coto A, et al. Hepatotoxicity due to hydroxycut: a case series. Am J Gastroenterol. 2010;105(7):1561–1566. PubMed.
- National Institute of Diabetes and Digestive and Kidney Diseases. LiverTox: Hydroxycut. Updated April 12, 2018. PubMed; NCBI Bookshelf.
- National Institute of Diabetes and Digestive and Kidney Diseases. LiverTox: Garcinia Cambogia. Updated February 13, 2019. PubMed; NCBI Bookshelf.
- Vuppalanchi R, Bonkovsky HL, Ahmad J, et al. Garcinia cambogia, either alone or in combination with green tea, causes moderate to severe liver injury. Clin Gastroenterol Hepatol. 2022;20(6):e1416–e1425. PubMed.
- van Breemen RB, Roe AL, Akhtar N. Hepatotoxicity of dietary supplements containing Garcinia gummi-gutta (L.) N. Robson. Pharm Biol. 2025;63(1):912–924. PubMed.
- Likhitsup A, Chen VL, Fontana RJ. Estimated exposure to 6 potentially hepatotoxic botanicals in US adults. JAMA Netw Open. 2024;7(8):e2425822. PubMed.
- Andueza N, Giner RM, Portillo MP. Risks associated with the use of Garcinia as a nutritional complement to lose weight. Nutrients. 2021;13(2):450. PubMed.
- Lopez AM, Kornegay J, Hendrickson RG. Serotonin toxicity associated with Garcinia cambogia over-the-counter supplement. J Med Toxicol. 2014;10(4):399–401. PubMed.
- Hendrickson BP, Shaikh N, Occhiogrosso M, Penzner JB. Mania induced by Garcinia cambogia: a case series. Prim Care Companion CNS Disord. 2016;18(2):15l01890. PubMed.
- Federal Trade Commission. Internet marketers of dietary supplement and skincare products banned from deceptive advertising and billing practices. Press release, November 15, 2017. FTC.
- Federal Trade Commission. FTC brings first case challenging fake paid reviews on an independent retail website. Press release, February 26, 2019. FTC.
- World Anti-Doping Agency. The 2026 Prohibited List. WADA 2026 Prohibited List.