Green Tea Extract (EGCG) for Obesity
BCochrane review of 14 RCTs found EGCG plus caffeine produces modest but statistically significant weight loss of 1.0-1.3 kg over 12 weeks. Twenty-four-hour energy expenditure increased approximately 5% and fat oxidation approximately 16%, with effects more pronounced in Asian populations and habitual low-caffeine consumers.
The Bottom Line
Cochrane review of 14 RCTs found EGCG plus caffeine produces modest but statistically significant weight loss of 1.0-1.3 kg over 12 weeks. Twenty-four-hour energy expenditure increased approximately 5% and fat oxidation approximately 16%, with effects more pronounced in Asian populations and habitual low-caffeine consumers.
Key Statistics
14
Studies
1500
Participants
Positive
Grade
Dosage & Usage
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units
Commonly Used Dosages
- general:
- 250-500 mg/day standardized to 50% EGCG
- equivalent:
- 3-5 cups green tea/day
- weightmanagement:
- 400-800 mg EGCG/day
Upper limit: 800 mg EGCG/day (hepatotoxicity risk above this; rare but documented)
Best taken: With meals (reduces nausea risk); avoid on empty stomach; space from iron-containing foods/supp
Safety & Side Effects
Reported Side Effects
- ⚠ Nausea on empty stomach
- ⚠ Insomnia (caffeine content)
- ⚠ Rare hepatotoxicity at high doses
- ⚠ Reduced iron absorption
Known Interactions
- ● Nadolol (reduced bioavailability)
- ● Iron supplements (reduced absorption)
- ● Blood thinners (theoretical)
- ● Other stimulants (additive effects)
Tolerable upper intake: 800 mg EGCG/day (hepatotoxicity risk above this; rare but documented)
Always consult your healthcare provider before starting any supplement.
Frequently Asked Questions
Does Green Tea Extract (EGCG) help with Obesity?
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Related Evidence
Other ingredients for Obesity
Green Tea Extract (EGCG) for other conditions
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.