Evidence-based·Last reviewed May 31, 2026·How we grade evidence

Hydroxycitric Acid

PhytochemicalOrganic acid

The active compound in Garcinia cambogia, sold for decades as a weight-loss aid. The largest and best-controlled trials (Heymsfield 1998 JAMA; Onakpoya 2011 meta-analysis) show no clinically meaningful weight loss versus placebo. Multiple case reports and the NIH LiverTox monograph link Garcinia-cambogia–containing products to acute liver injury, including fatal and transplant-requiring cases.

Quick decision guide

May help most

Honestly: nothing well-supported. Marketing claims for weight loss are not backed by high-quality RCTs.

Common dosing range

Trials used 1500–2800 mg HCA/day from Garcinia cambogia extract (50–60% HCA), typically split before meals.

When to expect effects

8–12 weeks in trials — most still showed no benefit over placebo.

Watch out for

Acute liver injury — including fatal cases and cases requiring liver transplant — is documented in the LiverTox monograph. Stop immediately for jaundice, dark urine, abdominal pain, or unusual fatigue.

Evidence snapshot

Weight loss vs placeboLow (null/minimal)

Fat-mass reductionLow

Appetite suppressionLow

Liver-injury safety signalModerate concern

What is it

Hydroxycitric acid (HCA) is a derivative of citric acid found in the rinds of Garcinia cambogia (also called Malabar tamarind) and other Garcinia species. It is one of the most popular ingredients in weight-loss supplements, often paired with chromium and other minerals.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You're aware that the best evidence shows no meaningful weight-loss benefit and you want to try it anyway, briefly, under medical supervision

You have no liver disease, take no hepatotoxic medications, and accept the documented hepatotoxicity risk

Probably skip if…

You're hoping for the weight loss the marketing promises — Heymsfield 1998 JAMA and Onakpoya 2011 meta-analysis show no clinically meaningful effect

You have any liver disease, hepatitis history, or take hepatotoxic medications (acetaminophen daily, methotrexate, isoniazid, etc.)

You're on an SSRI, SNRI, or other serotonergic medication — risk of serotonin syndrome

You're taking diabetes medications — HCA may compound hypoglycemia

You're pregnant or breastfeeding

You drink alcohol regularly — compounds liver-injury risk

You take other supplements stacked into proprietary 'weight-loss' formulas — many liver-injury cases involve combination products

Evidence at a glance

Goal	Effect	Best fit	Time
Appetite suppression Mixed Evidence	No consistent appetite-suppression effect in controlled trials; some VAS hunger-rating improvements in industry trials, not durable on objective intake measures	None established	Not established
Lipid / cardiometabolic markers Mixed Evidence	Inconsistent small effects on lipids in low-quality trials	None — lipid management has much better-evidenced options	Not reliably established
Weight loss Weak Evidence	Heymsfield 1998: no significant difference vs placebo (3.2 vs 4.1 kg over 12 weeks). Onakpoya 2011 pooled: −0.88 kg vs placebo (95% CI −1.75 to −0.00) — minimal and 'of doubtful clinical relevance.'	None established — the negative finding is consistent across the highest-quality trials	Trials ran 8–12 weeks — most still showed null results

Appetite suppression

Mixed Evidence

Effect: No consistent appetite-suppression effect in controlled trials; some VAS hunger-rating improvements in industry trials, not durable on objective intake measures
Best fit: None established
Time: Not established

Lipid / cardiometabolic markers

Mixed Evidence

Effect: Inconsistent small effects on lipids in low-quality trials
Best fit: None — lipid management has much better-evidenced options
Time: Not reliably established

Weight loss

Weak Evidence

Effect: Heymsfield 1998: no significant difference vs placebo (3.2 vs 4.1 kg over 12 weeks). Onakpoya 2011 pooled: −0.88 kg vs placebo (95% CI −1.75 to −0.00) — minimal and 'of doubtful clinical relevance.'
Best fit: None established — the negative finding is consistent across the highest-quality trials
Time: Trials ran 8–12 weeks — most still showed null results

Evidence for 3 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Appetite suppression

Mechanism only

Mixed Evidence

HCA is hypothesized to suppress appetite via central serotonergic effects and to inhibit ATP-citrate lyase (limiting fat synthesis from carbohydrate). The mechanism is real in vitro, but human appetite or food-intake outcomes in RCTs are inconsistent. Heymsfield 1998 specifically reported no significant appetite suppression. Some smaller trials with proprietary extracts reported modest hunger-rating improvements that did not translate to body-weight change.

Effect size

No consistent appetite-suppression effect in controlled trials; some VAS hunger-rating improvements in industry trials, not durable on objective intake measures

Time to effect

Not established

Best fit

None established

Less likely

People hoping appetite suppression will produce weight loss — it has not in trials

Bottom line: Mechanism doesn't translate to durable appetite reduction in humans.

SourceHeymsfield et al., 1998 — JAMA

Lipid / cardiometabolic markers

Mechanism only

Mixed Evidence

A handful of small trials have reported modest improvements in total cholesterol, LDL, or triglycerides with HCA-containing extracts. Effect sizes are small, trials are short, and the changes have not been replicated in larger or independent studies. Onakpoya 2011 did not pool a clear cardiometabolic benefit. There's no reason to take HCA for lipid management — established treatments (statins, lifestyle, fibre) are far better evidenced and safer.

Effect size

Inconsistent small effects on lipids in low-quality trials

Time to effect

Not reliably established

Best fit

None — lipid management has much better-evidenced options

Less likely

Anyone with established CV risk who should be on guideline-based therapy

Bottom line: Not a cholesterol or cardiometabolic supplement.

SourceOnakpoya et al., 2011 — Journal of Obesity

Weight loss

Supplement benefit

Weak Evidence

The Heymsfield 1998 JAMA trial — the most rigorous early study — randomised 135 overweight adults to 1500 mg HCA/day or placebo for 12 weeks on a fibre-rich diet. The placebo group lost slightly MORE weight (4.1 kg vs 3.2 kg), with no significant between-group difference. Onakpoya's 2011 systematic review pooled 12 RCTs and found a mean weight-loss difference of only −0.88 kg (95% CI just touching zero), which the authors described as 'of doubtful clinical relevance.' Even taking the favourable end of that confidence interval at face value, you're talking about under 2 lbs over 8–12 weeks — within measurement noise for a typical weight-loss program. The marketing claim that HCA produces meaningful weight or fat loss is not supported by high-quality evidence.

Effect size

Heymsfield 1998: no significant difference vs placebo (3.2 vs 4.1 kg over 12 weeks). Onakpoya 2011 pooled: −0.88 kg vs placebo (95% CI −1.75 to −0.00) — minimal and 'of doubtful clinical relevance.'

Time to effect

Trials ran 8–12 weeks — most still showed null results

Best fit

None established — the negative finding is consistent across the highest-quality trials

Less likely

Anyone counting on HCA for clinically meaningful weight loss

Bottom line: Do not take HCA expecting weight loss. The best evidence says it doesn't work, and there is a real liver-injury safety signal.

Evidence is mixed

Smaller industry-sponsored trials and proprietary-blend products (e.g. 'Super CitriMax') have published positive results; the largest, best-controlled independent trials (Heymsfield JAMA 1998) and the Onakpoya 2011 systematic review are negative. The pattern — positive industry trials, null independent trials — is the same one seen with many debunked weight-loss supplements.

SourceHeymsfield et al., 1998 — JAMA· conflicting Onakpoya et al., 2011 — Journal of Obesity· conflicting

SourceHeymsfield et al., 1998 — JAMA Onakpoya et al., 2011 — Journal of Obesity MSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center

How it works

HCA is best known as an inhibitor of ATP-citrate lyase, the enzyme that converts citrate into acetyl-CoA, a key step in the synthesis of fatty acids from carbohydrates. By inhibiting this enzyme, HCA theoretically reduces the body's ability to convert excess carbohydrates into stored fat. HCA may also enhance the production of glycogen, increase satiety signals, and modestly affect serotonin levels, which has been proposed as a mechanism for appetite suppression. Human trials have produced inconsistent results. While some studies show modest reductions in food intake and small weight loss compared with placebo, larger and more rigorous trials have often failed to find clinically meaningful effects. Standardization and the calcium/potassium salt form of HCA appear to influence outcomes.

How to take it

1. Typical dose

• Trials used 1500–2800 mg HCA/day from Garcinia cambogia extract • Standardised extracts are typically 50–60% HCA, so 1500 mg HCA = ~2500–3000 mg extract • Split into 2–3 doses 30–60 min before main meals • Note: even at the highest studied doses, weight-loss benefits were not clinically meaningful

2. Higher studied dose

Up to 2800 mg HCA/day has been used in clinical trials without acute toxicity in the trial period. However, the LiverTox monograph documents idiosyncratic acute liver injury at typical commercial doses — there is no safe-dose threshold for the hepatotoxicity signal.

3. Timing

30–60 minutes before main meals is the marketed approach (to coincide with the proposed ATP-citrate lyase inhibition during food absorption). Whether timing affects results is moot — the effect itself isn't clinically meaningful.

4. With food

Before meals (empty stomach) is the marketed approach.

5. Split dosing

Split into 2–3 pre-meal doses if you choose to try it. Single large doses haven't been better studied.

6. How long to try

Trials ran 8–12 weeks. If you choose to try HCA, set a clear stop point (8 weeks) and a clear success criterion (e.g. ≥5% body weight loss); discontinue if not met. Do not take continuously for months — the liver-injury risk accumulates.

What to track

Body weight — set a clear 8-week success criterion and stop if not met

Liver-injury warning signs: jaundice (yellow skin/eyes), dark urine, light-coloured stools, right-upper-quadrant pain, persistent fatigue, nausea — STOP IMMEDIATELY and see a clinician

Mood and energy — HCA's serotonergic activity can interact with SSRIs/SNRIs

Blood glucose if you have diabetes or take glucose-lowering drugs — risk of hypoglycemia

ALT/AST baseline and at 4–8 weeks if you choose to use it long-term (rarely done in practice, but reasonable given the safety signal)

Bottom line: If you're going to try it despite the evidence, do it for ≤8 weeks under medical supervision, with a clear stop criterion, baseline liver-function tests, and zero tolerance for any sign of liver injury.

3 commercial forms

Compare the main delivery options and what they’re best suited for.

Garcinia cambogia extract (50–60% HCA)

Most common

The standardised dried fruit-rind extract used in most clinical trials and most commercial products. Onakpoya 2011 pooled trials using this form. Evidence base is the strongest of any HCA form — and that evidence is largely null for weight loss.

Standard reference form; absorbed orally with mineral-salt-dependent bioavailability.

Calcium / potassium hydroxycitrate (CitriMax, Super CitriMax)

Proprietary salt

Patented mineral-salt forms (e.g. Ca/K hydroxycitrate, 'Super CitriMax') marketed for better bioavailability. The positive trials in the literature mostly use these proprietary salts and have been criticised for methodological limitations. Bioavailability advantage doesn't translate to a clinically meaningful weight-loss advantage.

Higher plasma HCA than free acid; clinical-outcome edge not established.

Magnesium hydroxycitrate

Less common

Alternative salt form. Limited independent data. Same overall efficacy and safety story as the broader HCA literature.

Similar to calcium hydroxycitrate.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

nauseaheadacheabdominal discomfortdiarrheadizziness

Serious risks

Acute liver injury — including jaundice, hepatocellular hepatitis, and rare cases of fulminant liver failure requiring transplantation or causing death. The NIH LiverTox monograph lists Garcinia cambogia as a 'likely cause' of acute liver injury in published case reports. The Italian Phytovigilance surveillance (Crescioli 2018) and the FDA's 2009 Hydroxycut recall both documented clusters of hepatotoxicity. Mechanism is unknown; suspected idiosyncratic immune-mediated injury. Risk is not predictable from dose.
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox Crescioli et al., 2018 — European Journal of Clinical Pharmacology Lunsford et al., 2016 — World Journal of Gastroenterology FDA MedWatch — Hydroxycut warning, 2009 — U.S. Food & Drug Administration
Serotonin syndrome — case reports of serotonin syndrome when HCA is combined with SSRIs, SNRIs, MAOIs, or other serotonergic drugs (including tramadol, triptans, dextromethorphan). HCA appears to have central serotonergic activity.
SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center
Hypoglycemia in people on diabetes medications — HCA may compound glucose-lowering, particularly with insulin, sulfonylureas, or meglitinides.
SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center
Mania or worsening psychiatric symptoms — case reports in patients with bipolar disorder taking Garcinia products.
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

Who should avoid it

Anyone with liver disease, hepatitis history, or elevated liver enzymes.
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox
People taking SSRIs, SNRIs, MAOIs, tramadol, triptans, or any serotonergic medication — risk of serotonin syndrome.
SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center
People on insulin, sulfonylureas, or other diabetes medications — risk of hypoglycemia.
SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center
Anyone taking hepatotoxic medications (high-dose acetaminophen, methotrexate, isoniazid, statins under monitoring, ART, anti-tuberculous therapy).
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox
People with bipolar disorder, dementia (some reports of worsening symptoms), or other psychiatric conditions.
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox
Heavy or daily alcohol users — additive hepatotoxicity risk.
SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

Pregnancy & breastfeeding

Avoid in pregnancy and breastfeeding. There are no adequate safety data, and given the documented hepatotoxicity in non-pregnant adults plus the lack of any established benefit, there is no acceptable risk/benefit ratio.

SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

Bottom line: HCA has well-documented hepatotoxicity — including transplant-requiring cases — for a supplement with no clinically meaningful proven benefit. The risk/benefit ratio is poor.

Interactions

SSRIs / SNRIs (sertraline, fluoxetine, escitalopram, venlafaxine, duloxetine)Major

Risk of serotonin syndrome — HCA appears to have central serotonergic activity. Case reports of confusion, agitation, hyperthermia, and tremor with the combination.

SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center

MAOIs, tramadol, triptans, dextromethorphanMajor

Same serotonin-syndrome mechanism. Avoid the combination.

SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center

hepatotoxic medications (high-dose acetaminophen, methotrexate, isoniazid, valproate)Major

Additive hepatotoxicity risk on top of HCA's idiosyncratic liver-injury signal. Avoid the combination.

SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

insulin, sulfonylureas, meglitinidesModerate

HCA may compound glucose-lowering and produce hypoglycemia. Monitor closely; consider dose-adjusting diabetes meds if you choose to use HCA.

SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center

warfarinModerate

Limited case-report evidence of altered INR with Garcinia-containing products. Monitor INR if combined.

SourceMSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center

statinsModerate

Both can affect liver enzymes; additive hepatotoxicity risk. Rare reports of muscle complications. Discuss with your prescribing clinician.

SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

alcoholModerate

Compounds hepatotoxicity risk. Avoid the combination, especially with heavy or daily drinking.

SourceLiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox

Food sources

Food	Amount	%DV
Garcinia cambogia (Malabar tamarind) — dried fruit rind	Used historically in South Asian cooking, sour curry flavouring	—
Garcinia indica (kokum) — dried fruit	Lower HCA content than G. cambogia	—

Garcinia cambogia (Malabar tamarind) — dried fruit rind

Amount: Used historically in South Asian cooking, sour curry flavouring
%DV: —

Garcinia indica (kokum) — dried fruit

Amount: Lower HCA content than G. cambogia
%DV: —

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Standardised to 50–60% HCA — the only meaningful specification

Single-ingredient Garcinia cambogia extract — avoid proprietary 'weight-loss blends' where you can't tell what's in it (most hepatotoxicity cases involved combination products)

Third-party tested (USP, NSF, ConsumerLab) — adulteration with synthetic sibutramine has been documented in weight-loss supplements

Mineral salt clearly labelled (calcium, potassium, magnesium, or chromium) — these affect absorption and the chromium combination adds another layer of considerations

Be skeptical of…

'Clinically proven for weight loss' — the highest-quality clinical evidence (JAMA 1998, Onakpoya 2011) is null or trivial

'Dr. Oz recommended' or similar TV-endorsement claims — the 'magic weight-loss cure' hype has been formally disavowed by the medical literature

'Block fat formation' — mechanism is real in vitro but doesn't translate to clinically meaningful fat loss in humans

Combination 'fat burner' products with caffeine, yohimbine, synephrine, ephedra, or undisclosed proprietary blends — these are the products most associated with hepatotoxicity case reports

Claims of liver-safety or liver-protective properties — the opposite is documented in the LiverTox monograph

'Natural' or 'safe because it's a fruit' — the case reports of liver failure leading to transplantation are also natural

Frequently asked questions

Does HCA / Garcinia really cause weight loss?⌄

Evidence is weak. Most well-controlled trials show small or no benefit beyond placebo. Effective weight management still depends primarily on diet and activity.

Is Garcinia cambogia safe for my liver?⌄

There have been case reports of liver injury linked to some Garcinia-containing products. The role of HCA itself versus other ingredients is unclear, but stop use immediately if liver symptoms appear.

Should I take HCA before or after meals?⌄

Most studies have used HCA 30-60 minutes before meals to align with its proposed effects on appetite and fat synthesis.

Can HCA replace exercise?⌄

No. Even with possible small effects on appetite, HCA does not produce meaningful weight loss without diet and activity changes.

Will HCA interact with my antidepressant?⌄

Possibly. HCA has been reported to affect serotonin pathways, and there are case reports of issues when combined with SSRIs. Consult your clinician.

References by claim

Weight loss

Onakpoya et al., 2011 — Journal of Obesity (2011) link

Heymsfield et al., 1998 — JAMA (1998) link

MSKCC About Herbs — Garcinia cambogia — Memorial Sloan Kettering Cancer Center (2024) link

Safety

Crescioli et al., 2018 — European Journal of Clinical Pharmacology (2018) link

LiverTox: Garcinia cambogia — NIH NCBI Bookshelf — LiverTox (2024) link

Lunsford et al., 2016 — World Journal of Gastroenterology (2016) link

FDA MedWatch — Hydroxycut warning, 2009 — U.S. Food & Drug Administration (2009) link

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Evidence-based·Last reviewed May 31, 2026·Evidence current as of May 31, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.