Epigallocatechin gallate

non-nutrient/non-botanical(-)-epigallocatechin 3-gallate

What is it

Epigallocatechin gallate (EGCG) is a polyphenolic flavan-3-ol catechin and the predominant bioactive compound in green tea. It is the gallic acid ester of epigallocatechin and accounts for the majority of green tea's antioxidant capacity.

How it works

EGCG exerts its effects through multiple molecular mechanisms. As a direct antioxidant, it neutralizes reactive oxygen species and chelates pro-oxidant metals. It modulates several intracellular signaling pathways, including activation of AMPK, inhibition of mTOR, and suppression of NF-kB-driven inflammation. Through these pathways, EGCG influences cellular metabolism, apoptosis, autophagy, and immune signaling. Research suggests EGCG inhibits enzymes such as catechol-O-methyltransferase and fatty acid synthase, which contributes to potential metabolic and thermogenic effects. It also binds the 67 kDa laminin receptor on cancer cells, prompting interest in oncology research. In vascular tissue, EGCG enhances endothelial nitric oxide synthase activity and may improve flow-mediated dilation. A major limitation is poor oral bioavailability. Plasma EGCG concentrations after typical supplementation are well below those that produce many in vitro effects. Bioavailability is improved by fasting administration but at increased safety risk, and reduced by milk, food, and certain co-administered nutrients.

Evidence for 5 uses

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

Antioxidant capacity

Grade B

Good evidence

EGCG reliably increases plasma antioxidant markers and reduces oxidative stress biomarkers in short-term studies.

Cardiometabolic markers

Grade C

Moderate evidence

EGCG supplementation has shown modest improvements in LDL cholesterol, blood pressure, and endothelial function across small trials. Effect sizes are clinically modest and population-dependent.

Body composition

Grade C

Moderate evidence

Trials of EGCG combined with caffeine demonstrate small increases in fat oxidation and modest weight reduction over weeks to months, particularly in caffeine-naive individuals.

Cognitive function

Grade D

Mixed evidence

Some studies suggest neuroprotective effects and improved cognitive performance, but evidence is preliminary and largely from older adults or those with mild cognitive impairment.

Cancer prevention or treatment

Grade F

Limited evidence

Despite extensive preclinical research, clinical trials in humans have not consistently demonstrated cancer prevention or treatment benefits. EGCG remains experimental in oncology.

3 commercial forms

Green tea extract capsules

EGCG percentage varies; typical bioavailability is low (around 0.1-1% systemic).

Standardized extracts are the most common supplement form. Read labels for actual EGCG content per serving.

Decaffeinated EGCG

Plasma levels may be slightly lower without caffeine co-administration.

Preferred for caffeine-sensitive individuals or evening dosing.

Bioavailability-enhanced formulations

Phospholipid or piperine combinations claim improved absorption.

Clinical evidence for meaningfully improved outcomes from enhanced bioavailability formulations is limited.

Dosage

There is no RDA. Clinical studies use a wide range, typically 200-800 mg per day. Daily supplemental intake above 800 mg has been flagged by EFSA as a hepatotoxicity concern. A safer typical range is 200-400 mg per day taken with food.

When and how to take it

Take with food to reduce hepatotoxicity risk and gastrointestinal discomfort. Earlier in the day is preferable when the formulation contains caffeine. If iron status is important, separate from iron supplements or iron-rich foods by 1-2 hours. Avoid empty-stomach dosing.

Food sources

Food	Amount	%DV
Brewed green tea (1 cup, 240 mL)	50-100 mg EGCG	—
Matcha (1 tsp powder)	60-80 mg EGCG	—
White tea (1 cup)	10-50 mg EGCG	—
Oolong tea (1 cup)	10-40 mg EGCG	—
Black tea (1 cup)	5-20 mg EGCG	—

Safety

Tolerability is generally good at moderate doses. Higher doses have been linked to elevated liver enzymes and rare cases of acute liver injury, especially when taken on an empty stomach. Gastrointestinal upset, nausea, and headache are the most common side effects. EGCG may reduce iron absorption when taken with food.

Who should be cautious

Avoid in people with liver disease, elevated liver enzymes, or a history of drug-induced liver injury. Pregnant and breastfeeding women should not use high-dose supplements due to limited safety data. People undergoing chemotherapy, especially with bortezomib, should consult an oncologist. Those with iron-deficiency anemia should separate dosing from iron supplements.

Interactions

EGCG inhibits multiple CYP450 enzymes and influences drug transporters, with documented potential to reduce absorption of nadolol and possibly other beta-blockers. It may reduce the efficacy of the cancer drug bortezomib. Combining with hepatotoxic medications, high-dose acetaminophen, or alcohol may increase liver injury risk. EGCG can interfere with iron absorption from supplements.

Frequently asked questions

How is EGCG different from green tea?⌄

Green tea contains many catechins; EGCG is the most abundant and best-studied one. Supplements may isolate or concentrate EGCG, while drinking tea provides EGCG plus other catechins, L-theanine, and caffeine.

What is a safe daily dose?⌄

Up to about 400 mg per day from supplements is widely considered safe when taken with food. Daily intakes above 800 mg have been flagged for liver risk.

Does EGCG help with weight loss?⌄

Modestly. Combined with caffeine and lifestyle changes, EGCG can slightly increase fat oxidation, but weight loss effects are small.

Why must I take it with food?⌄

Taking EGCG with food substantially reduces the risk of liver injury and gastrointestinal upset. Empty-stomach dosing increases plasma concentrations but raises safety risks.

Can I get enough EGCG from drinking tea?⌄

Yes, several cups of green tea per day provide a meaningful EGCG intake with very low risk. Drinking tea is the safest way to consume EGCG.

References

EFSA: EGCG Safety Opinion — European Food Safety Authority link
Wikidata: Epigallocatechin gallate — Wikidata link
PubChem: EGCG — PubChem link

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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.