Garcinia Cambogia

Garcinia cambogia is the sour, pumpkin-shaped fruit of the Malabar tamarind tree (Garcinia gummi-gutta): its dried rind has long soured fish curries in southern India and Sri Lanka, and its main acid, hydroxycitric acid (HCA), made it one of the most popular weight-loss supplements. In people the evidence is thin: a large, rigorous trial published in JAMA in 1998 found no extra weight loss at all, and later pooled analyses of small, short trials found only about 1 kg (2–3 lb) more than placebo. Against that small, uncertain benefit sits a rare but serious risk — liver injury severe enough to need a transplant, and manic or serotonin reactions — which is why this page spends as long on safety as on benefits.

Table of Contents

  1. What It Is: The Malabar Tamarind
  2. Traditional and Culinary Use
  3. What Is Actually in It
  4. How HCA Is Supposed to Work — and Why It Mostly Doesn’t in People
  5. Weight Loss: What the Human Trials Found
  6. Appetite and the Serotonin Claim
  7. Blood Sugar and Cholesterol
  8. How People Use It
  9. Myths and Overclaims in Popular Videos
  10. Safety, Interactions and Who Should Avoid It
  11. Key Research Papers
  12. Connections
  13. Featured Videos

What It Is: The Malabar Tamarind

“Garcinia cambogia” is the name on the supplement bottle, but botanists now call the tree Garcinia gummi-gutta; “cambogia” is an older synonym that stuck in marketing. It is an evergreen tree native to India and Southeast Asia. Its small fruit looks like a miniature pumpkin, and the part people use is the sour rind, usually dried for storage. The English common name, Malabar tamarind, points to the Malabar Coast of southwestern India. In Sri Lanka the same fruit is called goraka.

Garcinia is a large genus of about 200 species of trees and shrubs, around 30 of them found in India. It includes the mangosteen, which is a cousin, not the same fruit. Despite the nickname, Malabar tamarind is not related to ordinary tamarind (Tamarindus indica), the pod-bearing tree of the legume family whose sticky brown pulp sours chutneys and pad thai. The two are simply sour ingredients that cooks use in similar ways. Our Tamarind page covers the other one.

What you can buy comes in two very different forms. The first is the dried rind, sold as a souring agent in South Asian groceries. The second is concentrated extract in capsules, tablets and gummies, standardised to a percentage of HCA and marketed for weight loss. Almost everything written about “Garcinia” online is really about the second form, and so is every safety problem described further down this page.

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Traditional and Culinary Use

In the kitchen, the dried rind gives a sharp, clean sourness to fish curries. That is its main and oldest use, and it is especially associated with the coastal cooking of Kerala and Karnataka in southern India (Anilkumar 2023). The U.S. National Institutes of Health’s liver-injury database, LiverTox, describes the fruit as a food preservative and flavouring agent, and it has been eaten for centuries across South and Southeast Asia.

There may be a sensible food-safety reason behind the fish pairing. Sri Lankan food chemists found that adding a goraka extract to fresh skipjack tuna in the laboratory stopped the fish from forming histamine as it aged. Histamine is the compound that makes spoiling fish cause allergy-like reactions. The extract worked by dropping the pH to about 3.2–3.6, while extracts of ordinary tamarind and bilimbi did not stop histamine forming (Thadhani 2002). This was a test-tube food-chemistry study, not a human trial. It fits the fruit’s traditional role as a preservative, but it was not a test of anyone’s health.

In traditional medicine the rind was used as a digestive and for bowel complaints, diarrhoea, intestinal worms, ulcers and rheumatism. Some traditions also used it for constipation, swelling (oedema) and irregular periods. Evidence tier: traditional use only. None of these uses has been tested in controlled human trials.

The modern story began in the laboratory. In 1965, chemists identified (−)-hydroxycitric acid as the principal acid in the fruit (Lewis & Neelakantan 1965). Animal research on how that acid affects fat-making followed, and by the time of the landmark 1998 JAMA trial, Garcinia was already being promoted with the claim that it lowered body weight and body fat in humans.

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What Is Actually in It

Supplements vary widely. Most contain about 20% to 60% HCA, and the extracts used in clinical trials were typically standardised to 50% or 60%. Some products pair the extract with calcium, potassium or chromium. Many more are multi-ingredient “fat-burner” blends in which Garcinia is only one of several active ingredients, which matters a great deal when something goes wrong (see Safety).

One more detail matters for safety: the whole extract is not the same as HCA alone. When researchers tested Garcinia extract against liver drug-processing enzymes in the laboratory, the extract blocked one of them (CYP2B6), but pure HCA did not. Other compounds in the rind are pharmacologically active, so “it’s just a fruit acid” undersells what is in the capsule.

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How HCA Is Supposed to Work — and Why It Mostly Doesn’t in People

The theory is elegant. When your cells have more fuel than they need, they can turn sugar into fat, a process called de novo lipogenesis (“making fat from scratch”). One step in that assembly line uses an enzyme called ATP-citrate lyase. It sits in the fluid of the cell and splits citrate into oxaloacetate and acetyl-CoA, the two-carbon building block from which fatty acids and cholesterol are made. HCA is shaped so much like citrate that it slips into the enzyme’s citrate slot and blocks it, which makes it a competitive inhibitor. That part is real, well-established biochemistry.

In rats and other laboratory animals, Garcinia extracts and HCA reduced food intake and slowed fat gain. Evidence tier: animal. Those results are the foundation of every “blocks fat” advertisement.

Here is the catch, and it is the single most important idea on this page: people barely use that assembly line. A 1999 review of the human evidence by a University of California, Berkeley nutrition scientist found that eating extra carbohydrate does not switch on liver fat-making in any substantial way as long as total carbohydrate calories stay below what you burn in a day. Instead, the body simply burns more carbohydrate and less fat. You still gain body fat if you overeat, but mostly by storing the fat you ate while the carbohydrate is burned in its place, not by converting sugar into new fat. Only when carbohydrate intake exceeds your entire daily energy expenditure does the fat-from-sugar pathway contribute meaningfully. Blocking it with HCA is like closing a side road that almost no traffic uses.

Researchers in the Netherlands put this to a direct test (Kovacs 2006). Ten lean young men were deliberately overfed for a week on a diet that was more than 85% carbohydrate and supplied 130–175% of their energy needs. This is exactly the extreme situation in which the pathway does switch on. They took 500 mg of HCA three times a day or a placebo, in a double-blind crossover design. Fat-making tended to be lower with HCA, but the difference did not reach statistical significance. Weight gain was the same either way: 2.9 kg on HCA and 2.8 kg on placebo. Evidence tier: small human crossover trial. If HCA cannot stop weight gain even under forced carbohydrate overfeeding, it is hard to see how it would melt fat during ordinary eating.

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Weight Loss: What the Human Trials Found

The 1998 JAMA trial: no difference

The landmark test was run at Columbia University’s obesity research centre in New York and published in JAMA in 1998. It randomly assigned 135 overweight adults (average BMI about 32) to 1,500 mg of HCA a day or a placebo for 12 weeks, under double-blind conditions. Both groups followed a high-fibre, reduced-calorie diet. Both groups lost a significant amount of weight, and the placebo group actually lost slightly more: 3.2 kg on Garcinia versus 4.1 kg on placebo, a difference that was not statistically significant. There was also no difference in body-fat loss. The authors’ conclusion was blunt: Garcinia cambogia “failed to produce significant weight loss and fat mass loss beyond that observed with placebo.” Evidence tier: randomised controlled trial, null result.

The trial also reveals why so many people feel Garcinia works. When the capsule comes packaged with a diet plan, the diet does the work, and in this trial it did the same work for the people swallowing a placebo.

A positive trial, with a twist

Not every trial was null. In a 12-week double-blind study of 89 mildly overweight women on a roughly 1,200-calorie diet, 42 took Garcinia (1.2 g of HCA a day, 30–60 minutes before meals) and 47 took a placebo. The Garcinia group lost more: 3.7 kg versus 2.4 kg. The same study, however, found no effect at all on hunger, fullness or any other appetite measure, which undercuts the usual explanation for how it is supposed to work. Evidence tier: randomised controlled trial, modest positive result for weight, null for appetite.

The pooled analyses: about a kilogram

Why those numbers deserve caution

The trials behind these averages are small and short. A review from Spain’s Rovira i Virgili University noted that most were run on small samples over a few weeks and that none showed whether any effect lasts beyond 12 weeks (Márquez 2012). A 2024 review of weight-loss supplements and drug interactions counted 20 human studies: 12 reported significant weight loss and the rest found none, and the studies differed widely in design, extract, dose and diet. When roughly half the trials are positive and the positive ones are small and brief, a pooled average of about a kilogram is best read as “possibly a little, possibly nothing, for a few months”.

Evidence tier overall: randomised trials in humans, small and short, with inconsistent results. A plausible short-term effect of roughly 1 kg (2–3 lb), with no evidence that it lasts past three months. For approaches with far stronger evidence, see our Weight Loss guide, its Realistic Expectations article and our Obesity page.

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Appetite and the Serotonin Claim

The second big selling point is that Garcinia “shuts off cravings” and “stops emotional eating” by raising serotonin, the brain chemical involved in mood and fullness. Here is what that claim rests on.

The laboratory finding. In 2001, researchers took thin slices of rat brain cortex and bathed them in HCA in a dish. HCA increased the release of labelled serotonin from the tissue, with the largest effect at a concentration of 300 micromolar, but it did not change the release triggered by a nerve-like stimulus. Evidence tier: in vitro, animal tissue. We found no study showing that swallowing Garcinia raises serotonin in a living human brain. When reviews say HCA regulates “serotonin levels related to satiety”, that phrase rests on laboratory experiments like this one, not on human brain measurements.

The human appetite studies disagree with one another.

The longest was the 12-week trial in 89 women described above. HCA had no effect on hunger or fullness, and the authors wrote that their study “does not support a satiety effect of HCA.”

A small crossover study at Maastricht University in 24 overweight adults found the opposite. After two weeks of 300 mg of HCA in tomato juice three times a day, they ate 15–30% fewer calories over 24 hours in a laboratory restaurant, with no change in how hungry they felt (Westerterp-Plantenga 2002).

A similar two-week crossover study of 21 adults by the same Maastricht group found no difference in fullness or calorie intake between HCA and placebo (Kovacs 2001).

Evidence tier: in vitro and animal for the mechanism; small, conflicting human studies for appetite. The serotonin story is weak as a weight-loss explanation, but it matters for safety. Several of the most serious reactions reported with Garcinia involve serotonin and mood, especially in people already taking antidepressants that raise serotonin (see Mania and serotonin toxicity). For how serotonin works, try our interactive Serotonin and Mood animation.

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Blood Sugar and Cholesterol

Blood sugar: no reliable effect

Because HCA acts on energy metabolism, Garcinia is often promoted for blood-sugar control, and it is often said to add to the effect of diabetes medicines. A 2025 meta-analysis pooled 9 randomised trials with 444 adults. It found no significant effect on fasting blood sugar (an average change of +1.02 mg/dL, not significant) or on fasting insulin. The subgroup results pointed in both directions: insulin rose in women and in people with a BMI of 30 or more, and fell in trials longer than 8 weeks. Scattered subgroup results like these are common when there is no consistent underlying effect. Evidence tier: meta-analysis of small randomised trials, null. Garcinia is not a treatment for type 2 diabetes, and the diabetes-related case reports discussed under Safety are not about predictable low blood sugar.

Cholesterol and triglycerides: small shifts, not in LDL

A 2024 meta-analysis of 14 trials with 623 people found modest average changes in blood fats with Garcinia:

LDL is the main target of cholesterol treatment. The authors flagged significant differences between trials and short durations, and called for well-designed long-term studies before the findings can be relied on. Evidence tier: meta-analysis of small, heterogeneous randomised trials; modest and uncertain. For the approaches with outcome evidence behind them, see Cholesterol Management.

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How People Use It

As food

The traditional way to meet this fruit is in the pot. A few pieces of the dried rind are simmered in a fish curry or other sour dish, playing the part that tamarind, lime or vinegar plays elsewhere. This is a seasoning amount, not a weight-loss dose, and nobody should expect a curry to change their weight. Culinary use is also not where the safety problems are: the published liver-injury cases involve concentrated weight-loss supplements, not the fruit cooked as food.

As a supplement

Our practical take

Enjoy the dried rind as a food. As a weight-loss supplement, the balance does not favour it: an average benefit of about a kilogram over a few months against a small but real chance of serious liver or psychiatric harm. A 2024 review of weight-loss supplements and drug interactions reached the same conclusion, that “the risk–benefit balance is not in favor of taking this supplement.”

If you decide to try it anyway, lower the risk in these ways:

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Myths and Overclaims in Popular Videos

Popular videos about Garcinia tend to repeat the same handful of claims. Here is how each one holds up.

What the videos get right is narrower than what they claim. HCA really does inhibit a fat-making enzyme, the fruit really is a traditional food, and pooled trials really do show a small short-term difference. The leap from those facts to “ultimate pill” is where the evidence runs out.

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Safety, Interactions and Who Should Avoid It

In most short trials, people taking Garcinia had no more side effects than people on placebo. The minor complaints reported include stomach upset, diarrhoea, gas, heartburn, headache, leg cramps and rash, and a 2025 meta-analysis found no average change in the liver enzymes ALT and AST. The concern is not a steady, dose-related strain on everyone’s liver. It is rare, unpredictable reactions in a few people, which small trials are too small to catch.

Liver injury: rare, unpredictable, sometimes severe

LiverTox, the liver-injury reference run by the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, states that weight-loss products labelled as containing Garcinia cambogia have been linked to clinically apparent acute liver injury that “can be severe and even fatal.”

The most careful evidence comes from the NIH-funded Drug-Induced Liver Injury Network (DILIN), which investigates suspected cases at U.S. medical centres. Among 1,418 patients enrolled between 2004 and 2018, experts attributed 22 cases, with high confidence, to Garcinia-containing products:

Liver injury from Garcinia products was clinically indistinguishable from injury caused by green tea extract products. Both ingredients have their own liver records (see EGCG Safety and Liver Health for green tea extract).

A 2021 review of 21 published cases of liver injury found the same picture. The usual symptoms were pain under the right ribs, nausea, vomiting, fatigue and abnormal liver tests. Most people recovered after stopping, but four needed liver transplants. For how this fits the wider problem of supplement-induced liver damage, see Liver Injury from Supplements.

Why multi-ingredient products muddy the picture

Of those 21 published cases, 16 involved blends that contained other active ingredients besides Garcinia. When a product with ten ingredients injures someone, no one can be sure which ingredient did it. A 2015 review concluded that Garcinia had not yet been confirmed as the culprit for exactly that reason. Injuries have also been reported with pure Garcinia extract or with Garcinia plus only vitamins and minerals, and the DILIN series included five single-ingredient cases. The honest reading is that Garcinia can injure the liver on its own, and that blends add unknowns on top.

A 2004 case shows the problem clearly. An otherwise healthy 54-year-old woman developed chest pain and rhabdomyolysis (muscle breakdown) after taking an herbal weight-loss product that combined ephedra, guarana (a caffeine source), chitosan, gymnema, Garcinia and chromium (Mansi 2004). With six active ingredients, including two stimulants, pinning the blame on any one of them is guesswork. Stimulant-laced blends have their own page: Stimulants in Weight-Loss and Energy Products.

Regulators have acted on the category. In 2009 the U.S. Food and Drug Administration warned consumers about a popular line of multi-ingredient weight-loss products after reports of serious liver injury, and the products were recalled. Only some of the formulas in that line contained Garcinia, and all were blends. Adulteration is a further unknown in this market, including undeclared prescription drugs found in “natural” slimming products (see Hidden Prescription Drugs). The whole landscape is mapped on our Dangerous Supplements hub.

Mania and serotonin toxicity

Serotonin toxicity with an antidepressant. Physicians at Oregon’s poison centre reported the case of a 35-year-old woman who had taken the SSRI antidepressant escitalopram for a year. After two to three months of a Garcinia product (60% HCA, with chromium, potassium and calcium), she developed:

These are the hallmarks of serotonin toxicity. She had not mentioned the supplement to her doctor, who stopped the escitalopram. When a different antidepressant was started two weeks later, she was admitted to hospital with serotonin toxicity, and both the antidepressant and the Garcinia were then stopped. This case is the clearest argument for telling every clinician about every supplement.

Mania. New York psychiatrists described three patients who became manic or hypomanic after one to two months of Garcinia (Hendrickson 2016):

Other reports describe hypomania in a woman with bipolar disorder who was taking the SSRI paroxetine, and mania with psychosis in a 22-year-old woman with no psychiatric history. In the reported cases, symptoms faded after the supplement was stopped. Evidence tier: case reports. They cannot prove cause, and reviewers stress that a causal link is not established. Still, the pattern of onset after starting, recovery after stopping and overlap with serotonin-raising drugs is why reviewers advise close monitoring for anyone with depression or bipolar disorder who takes it.

Other reported reactions

Isolated case reports describe acute pancreatitis in an 82-year-old man who had had pancreatitis before. A 56-year-old woman with insulin-treated diabetes, high blood pressure and chronic hepatitis C developed diabetic ketoacidosis, pancreatitis and stress-related heart-muscle weakness after taking a Garcinia supplement (1,400 mg of HCA a day); a standard causality score rated the supplement a probable cause. Evidence tier: single case reports.

Drug interactions

Very few formal interaction studies exist. The cautions below come from case reports, laboratory findings and pharmacological reasoning, so treat them as reasons for care, not as measured risks.

Who should avoid it

Warning signs: stop and get checked

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Key Research Papers

  1. Semwal RB, Semwal DK, Vermaak I, Viljoen A (2015). A comprehensive scientific overview of Garcinia cambogia. Fitoterapia. — PubMed PMID: 25732350
  2. Hellerstein MK (1999). De novo lipogenesis in humans: metabolic and regulatory aspects. European Journal of Clinical Nutrition. — PubMed PMID: 10365981
  3. Heymsfield SB, Allison DB, Vasselli JR, Pietrobelli A, Greenfield D, Nunez C (1998). Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA. — PubMed PMID: 9820262
  4. Mattes RD, Bormann L (2000). Effects of (-)-hydroxycitric acid on appetitive variables. Physiology & Behavior. — PubMed PMID: 11134690
  5. Ohia SE, Awe SO, LeDay AM, Opere CA, Bagchi D (2001). Effect of hydroxycitric acid on serotonin release from isolated rat brain cortex. Research Communications in Molecular Pathology and Pharmacology. — PubMed PMID: 11758650
  6. Onakpoya I, Hung SK, Perry R, Wider B, Ernst E (2011). The Use of Garcinia Extract (Hydroxycitric Acid) as a Weight loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Journal of Obesity. — PubMed PMID: 21197150
  7. Golzarand M, Omidian M, Toolabi K (2020). Effect of Garcinia cambogia supplement on obesity indices: A systematic review and dose-response meta-analysis. Complementary Therapies in Medicine. — PubMed PMID: 32951714
  8. Amini MR, Rasaei N, Jalalzadeh M, Akhgarjand C, Hashemian M, Jalali P, Hekmatdoost A (2024). The effects of Garcinia cambogia (hydroxycitric acid) on lipid profile: A systematic review and meta-analysis of randomized controlled trials. Phytotherapy Research. — PubMed PMID: 38151892
  9. Tavakoli S, Amini MR, Rabiee R, Salavatizadeh M, Afsharianfar M, Askarpour M, Hekmatdoost A (2025). The effects of Garcinia cambogia on glycaemic control and liver enzymes in adults: a systematic review and meta-analysis of randomised controlled trials. Journal of Nutritional Science. — PubMed PMID: 39943939
  10. Vuppalanchi R, Bonkovsky HL, Ahmad J, et al.; Drug-Induced Liver Injury Network (2022). Garcinia cambogia, Either Alone or in Combination With Green Tea, Causes Moderate to Severe Liver Injury. Clinical Gastroenterology and Hepatology. — PubMed PMID: 34400337
  11. National Institute of Diabetes and Digestive and Kidney Diseases (2012–). Garcinia Cambogia. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. — PubMed PMID: 31643417
  12. Andueza N, Giner RM, Portillo MP (2021). Risks Associated with the Use of Garcinia as a Nutritional Complement to Lose Weight. Nutrients. — PubMed PMID: 33572973
  13. Lopez AM, Kornegay J, Hendrickson RG (2014). Serotonin toxicity associated with Garcinia cambogia over-the-counter supplement. Journal of Medical Toxicology. — PubMed PMID: 24699886
  14. Rivas García F, García Sierra JA, Valverde-Merino MI, Zarzuelo Romero MJ (2024). Dietary Supplements for Weight Loss and Drug Interactions. Pharmaceuticals. — PubMed PMID: 39770500

PubMed Topic Searches

  1. PubMed: Garcinia cambogia weight-loss trials
  2. PubMed: Garcinia cambogia and liver injury
  3. PubMed: Garcinia cambogia, mania and serotonin toxicity

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Connections

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