Magnesium hydroxycitrate

MineralMagnesiumBest with a meal

What is it

Magnesium hydroxycitrate is a magnesium salt of hydroxycitric acid (HCA), the active compound in Garcinia cambogia. It is used in weight-management supplements as a stable, bioavailable form of HCA, and as a research tool for inhibiting kidney stone formation.

Evidence for 2 uses

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

Calcium oxalate kidney stone prevention

Limited Evidence

Animal studies and small human studies suggest magnesium hydroxycitrate may inhibit calcium oxalate stone formation, potentially more effectively than potassium citrate. Larger trials are needed.

Weight management

Mixed Evidence

HCA salts overall show small or no effect on weight in clinical trials. Specific evidence for magnesium hydroxycitrate is limited.

How it works

Hydroxycitric acid inhibits ATP-citrate lyase, an enzyme involved in fatty acid synthesis. This was the basis for marketing Garcinia/HCA products for weight loss; however, clinical trials have generally shown small or no effect on body weight or fat. Magnesium hydroxycitrate has been studied as an effective inhibitor of calcium oxalate kidney stone formation in animal models and small human studies, where it appears more potent than potassium citrate.

Dosage

For weight management: HCA salts typically 1.5 to 3 g per day. For kidney stone studies: variable; under medical supervision.

When and how to take it

For weight management, HCA salts are typically taken 30 to 60 minutes before meals. For kidney stone prevention research, typically taken with meals.

1 commercial form

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

Magnesium hydroxycitrate

Used in weight-management supplements and kidney stone research.

Provides bioavailable magnesium plus HCA.

Safety

Generally well tolerated at typical doses. HCA-containing products have rare reports of hepatotoxicity, though magnesium hydroxycitrate specifically has limited safety data. Magnesium content may cause loose stools.

Who should be cautious

Avoid in pregnancy and breastfeeding. Caution in people with kidney disease (risk of magnesium accumulation). People with liver disease should avoid HCA products. Discuss with a clinician if you have a history of kidney stones.

Interactions

Magnesium can reduce absorption of some antibiotics (tetracyclines, fluoroquinolones), bisphosphonates, and levothyroxine; separate by 2 to 4 hours. HCA may potentiate effects of statins on lipid metabolism (theoretical).

Frequently asked questions

Does it really help weight loss?⌄

HCA-based supplements as a category show minimal weight loss effects in trials.

Does it help with kidney stones?⌄

Early research suggests it inhibits calcium oxalate crystal growth. Larger human trials are needed before it can be recommended for stone prevention.

References

Magnesium hydroxycitrate on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Magnesium hydroxycitrate (PubMed search) — PubMed link

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Evidence-based·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.