“Green tea extract helps you lose weight.”
Green tea extract adds little to weight loss; in most trials the difference was too small to matter.
Green tea extract is not a useful weight-loss tool for most people. The average extra loss in trials was small, and concentrated extracts carry a rare risk of serious liver injury.
If you are thinking about a green tea extract for weight loss, skip it or talk with a healthcare professional first; brewed green tea as a drink is a different, low-risk choice.
Safety note: Concentrated green tea extracts can cause rare but sometimes serious liver injury. Extracts can also cause nausea, stomach discomfort and higher blood pressure, and can lower blood levels of some medicines, including the beta-blocker nadolol and the cholesterol drug atorvastatin.
Talk to a healthcare professional if: you have liver disease, you take nadolol, atorvastatin or other daily medicines, or you get yellow skin or eyes, dark urine or belly pain while taking a green tea extract.
A Cochrane review of 18 trials found weight changes too small to matter, and a newer review found only a small extra effect when green tea was added to exercise. Confidence is Moderate because products, doses and caffeine content differ and most trials lasted about 3 months.
Green tea extract adds little to weight loss; in most trials the difference was too small to matter. Outside Japan, pooled trials found people on green tea lost about 0.1 pound more than people on a placebo over 12 to 13 weeks.
Trials in Japan were too different to pool, and showed extra losses from about 0.4 to 7.7 pounds. The Cochrane authors judged the effect not likely to be clinically important and found no help with keeping weight off. A 2024 review of 10 trials found that adding green tea catechins to exercise gave a small but consistent extra drop in weight and body fat, which its authors called "quite minimal". The US National Center for Complementary and Integrative Health says any effect on weight is modest and depends on the product and how active a person is. Drinking green tea and taking a concentrated extract are different exposures.
- Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database of Systematic Reviews. 2012;(12):CD008650. DOI: 10.1002/14651858.CD008650.pub2. PMID: 23235664. PMCID: PMC8406948
- Gholami F, Antonio J, Iranpour M, Curtis J, Pereira F. Does green tea catechin enhance weight-loss effect of exercise training in overweight and obese individuals? A systematic review and meta-analysis of randomized trials. Journal of the International Society of Sports Nutrition. 2024;21(1):2411029. DOI: 10.1080/15502783.2024.2411029. PMID: 39350601. PMCID: PMC11445908
- National Center for Complementary and Integrative Health. Green Tea. Last updated February 2025