tuneTypical Dose
400-500
Natural Compound
EGCG
Epigallocatechin gallate
Evidence TierBWADA NOT PROHIBITED
watchEffect Window
Acute metabolic effects within hours. Durable fat-loss outcomes at 8-12 weeks.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
EGCG is the main green tea catechin with antioxidant and cell signaling effects. It is used for cardiometabolic support, fat oxidation, and modulation of inflammation-related biomarkers.
Human data still support only modest body-composition and oxidative-stress effects, usually in the context of green tea extract rather than isolated EGCG. A newer grade-assessed meta-analysis found small reductions in body mass, BMI, body-fat percentage, and malondialdehyde, but not in fat mass itself. Concentrated extracts still carry a meaningful liver-injury caution, so EGCG works better as a modest adjunct than as a dramatic fat-loss supplement.
Inhibits COMT to prolong catecholamine activity, enhancing thermogenesis and fat oxidation. Acts as a potent free radical scavenger and inhibits alpha-amylase.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Increases fat oxidation and 24h energy expenditure, especially with caffeine
- Antioxidant cardiovascular support
Secondary Outcomes
- Reduces LDL cholesterol
- Potential cancer-preventive properties (observational only)
Safety
Contraindications and Interactions
Contraindications
- Liver disease
- Iron deficiency (inhibits non-heme iron absorption)
Side effects
- Nausea
- GI upset on empty stomach
- Insomnia (caffeine content)
- Hepatotoxicity at high doses (concentrated supplements)
Interactions
- Inhibits COMT (increases catecholamine levels)
- Reduces nadolol bioavailability
- May reduce bortezomib efficacy
- Affects folic acid metabolism
- Chelates non-heme iron
Avoid if
- Liver disease
- Iron deficiency anemia
- Pregnancy or lactation without clinician review
Evidence
Study-level References
egcg-SRC-001Human randomized crossover trial
Sourceopen_in_newDulloo AG, 1999 (RCT crossover)
Population: Adults
Dose protocol: Green tea extract intervention with EGCG/caffeine dosing (approx. 270mg EGCG + 150mg caffeine)
Key findings: 4% increase in 24h energy expenditure in crossover comparison.
Notes: Source maps to Dulloo AG's RCT crossover results. Effect magnitude should be interpreted with formulation and caffeine context.
Paper content
4% increase in 24h energy expenditure in crossover comparison.
egcg-SRC-002Systematic review and dose-response meta-analysis
Sourceopen_in_newThe effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials. Br J Nutr. 2024. doi:10.1017/S000711452300260X. PMID:38031409.
Population: Adults enrolled in green tea extract randomized controlled trials.
Dose protocol: Green tea extract across 59 randomized trials with dose-response meta-analysis
Key findings: Pooled effects favored green tea extract for body mass, BMI, body-fat percentage, malondialdehyde, adiponectin, and total antioxidant capacity, while fat mass and several appetite hormones remained unchanged.
Notes: Best modern summary for keeping weight and oxidative-stress claims modest instead of dramatic.
Paper content
Across 59 randomized trials, green tea extract produced small improvements in body mass, BMI, body-fat percentage, oxidative-stress markers, adiponectin, and total antioxidant capacity, while leaving fat mass and several appetite hormones unchanged. This helps keep EGCG and green tea extract claims modest rather than dramatic.