EGCG (Epigallocatechin Gallate)
Antioxidant ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
EGCG is the most abundant and biologically active catechin in green tea (Camellia sinensis) and is sold as a standardized polyphenol extract for metabolic, cardiovascular, and antioxidant support. It is studied for modest effects on body weight, blood lipids, and vascular function, largely attributed to its potent free-radical-scavenging and enzyme-modulating activity. Because it is concentrated far above the levels found in brewed tea, supplemental EGCG carries dose-dependent safety considerations not seen with ordinary tea drinking.
Exploratory record, not a reviewed medical publication.
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This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
EGCG (Epigallocatechin Gallate) is an antioxidant most often used for provides potent antioxidant and free-radical scavenging activity, supports modest weight management and fat oxidation, especially with exercise, may improve blood lipid profile (total and ldl cholesterol). NutriStack rates the overall evidence as moderate. A typical adult dose is Typically 250-500 mg of EGCG per day; total daily intake from supplements should generally stay at or below 800 mg to limit liver-injury risk, commonly taken as standardized green tea extract stating egcg content; taken with food to reduce hepatotoxicity risk. This profile indexes 9 sources.
- Provides potent antioxidant and free-radical scavenging activity1
- Supports modest weight management and fat oxidation, especially with exercise7,5
- May improve blood lipid profile (total and LDL cholesterol)2,3
- Supports cardiovascular and endothelial function3
- May modestly improve blood glucose regulation2,3
The bottom line
Evidence rating moderate. Most-documented uses: provides potent antioxidant and free-radical scavenging activity, supports modest weight management and fat oxidation, especially with exercise, may improve blood lipid profile (total and ldl cholesterol). 9 sources indexed (1999–2018), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
EGCG is a powerful direct antioxidant that scavenges reactive oxygen and nitrogen species and chelates pro-oxidant transition metals such as iron and copper, while also upregulating endogenous antioxidant defenses through activation of the Nrf2/ARE pathway. Metabolically, it inhibits catechol-O-methyltransferase (COMT), prolonging the action of norepinephrine and thereby supporting thermogenesis and fat oxidation, and it inhibits intestinal lipases and alpha-amylase to reduce dietary fat and carbohydrate absorption. EGCG also modulates AMPK signaling, suppresses lipogenic and inflammatory transcription factors (including NF-kB), and improves endothelial function by enhancing nitric oxide bioavailability. Its bioavailability is low and it undergoes extensive glucuronidation, sulfation, and methylation, which limits systemic exposure relative to ingested dose.1,7
Dosing & protocol.
EGCG is water-soluble with inherently low oral bioavailability. While fasting can increase peak plasma levels, concentrated EGCG taken on an empty stomach is associated with greater risk of liver injury, so authoritative guidance recommends taking it with food. Co-ingestion with vitamin C or piperine may modestly improve stability and absorption; calcium, iron, and milk proteins can reduce it.1,3
What it actually costs.
Real-world pricing across three quality tiers. Assumes Standardized decaffeinated green tea extract capsule.
Budget tier reflects bulk standardized green tea extract capsules (200 to 400 mg EGCG/dose); mid tier reflects branded decaffeinated, third-party-tested extracts; premium reflects phytosome / enhanced-absorption formulations sold at a lower effective milligram dose. Brewed green tea is comparable or cheaper per dose if buying loose-leaf or bagged tea. Prices are approximate US retail per effective daily EGCG dose. Updated 2026-06-04.
Full safety detail.
Side effects
- Nausea and stomach upset (more likely on an empty stomach)
- Liver enzyme elevation and rare idiosyncratic hepatotoxicity at high doses
- Headache or dizziness
- Caffeine-related jitteriness or insomnia if the extract is not decaffeinated
- Constipation
Contraindications
- Pre-existing liver disease or elevated liver enzymes1
- Pregnancy and breastfeeding (high-dose supplements; may inhibit folate metabolism)1
- Concurrent use with hepatotoxic medications1,9
- Use with the chemotherapy agent bortezomib (EGCG can block its activity)1,7
- Anticoagulant or antiplatelet therapy without medical supervision
- Known iron-deficiency anemia (EGCG inhibits non-heme iron absorption)
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
7- 1Scientific opinion on the safety of green tea catechinsEFSA Panel on Food Additives and Nutrient Sources added to Food · EFSA Journal · 2018
Doses of EGCG at or above 800 mg/day from supplements were associated with statistically significant increases in serum transaminases, signaling potential liver injury.
- 2Green tea catechins and blood pressure: a systematic review and meta-analysis of randomised controlled trialsSource linkedPMIDKhalesi S, Sun J, Buys N, Jamshidi A, Nikbakht-Nasrabadi E, Khosravi-Boroujeni H · European Journal of Nutrition · 2014
- 3Green tea consumption and cardiovascular outcomes: a systematic review and meta-analysisHartley L et al. · Cochrane Database of Systematic Reviews · 2013
Green tea consumption was associated with favorable reductions in blood pressure and LDL cholesterol, suggesting a cardiovascular benefit, though long-term outcome data were limited.
- 4Effect of green tea on glucose control and insulin sensitivity: a meta-analysis of 17 randomized controlled trialsSource linkedPMIDLiu K, Zhou R, Wang B, Chen K, Shi LY, Zhu JD, Mi MT · American Journal of Clinical Nutrition · 2013
- 5Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trialsZheng XX et al. · American Journal of Clinical Nutrition · 2011
Green tea consumption significantly reduced total cholesterol and LDL cholesterol compared with control, with no significant effect on HDL cholesterol.
- 6Green tea extract and catechin ameliorate chronic fatigue-induced oxidative stress and the effect of green tea catechins on serum lipidsSource linkedPMIDZheng XX, Xu YL, Li SH, Liu XX, Hui R, Huang XH · American Journal of Clinical Nutrition · 2011
- 7The effects of green tea on weight loss and weight maintenance: a meta-analysisHursel R et al. · International Journal of Obesity · 2009
Green tea catechin-caffeine mixtures significantly reduced body weight and helped maintain weight after a period of weight loss, with effects modulated by habitual caffeine intake.
Randomized controlled trials
1- 8Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humansDulloo AG et al. · American Journal of Clinical Nutrition · 1999
A green tea extract increased 24-hour energy expenditure and fat oxidation beyond what could be attributed to its caffeine content alone.
Reviews & position papers
1- 9Hepatotoxicity of green tea: an updateSource linkedPMIDMazzanti G, Di Sotto A, Vitalone A · Archives of Toxicology · 2015
Common questions.
Quick answers about EGCG (Epigallocatechin Gallate), drawn from the data on this page.
What is EGCG (Epigallocatechin Gallate)?
EGCG is the most abundant and biologically active catechin in green tea (Camellia sinensis) and is sold as a standardized polyphenol extract for metabolic, cardiovascular, and antioxidant support. It is studied for modest effects on body weight, blood lipids, and vascular function, largely attributed to its potent free-radical-scavenging and enzyme-modulating activity. Because it is concentrated far above the levels found in brewed tea, supplemental EGCG carries dose-dependent safety considerations not seen with ordinary tea drinking.
What is EGCG (Epigallocatechin Gallate) used for?
Commonly cited benefits of EGCG (Epigallocatechin Gallate) include: Provides potent antioxidant and free-radical scavenging activity; Supports modest weight management and fat oxidation, especially with exercise; May improve blood lipid profile (total and LDL cholesterol); Supports cardiovascular and endothelial function; May modestly improve blood glucose regulation. NutriStack rates the overall evidence as moderate.
What is a typical dose of EGCG (Epigallocatechin Gallate)?
A typical adult dose of EGCG (Epigallocatechin Gallate) is Typically 250-500 mg of EGCG per day; total daily intake from supplements should generally stay at or below 800 mg to limit liver-injury risk. The commonly recommended form is Standardized green tea extract stating EGCG content; taken with food to reduce hepatotoxicity risk. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of EGCG (Epigallocatechin Gallate)?
Reported side effects include nausea and stomach upset (more likely on an empty stomach), liver enzyme elevation and rare idiosyncratic hepatotoxicity at high doses, headache or dizziness, caffeine-related jitteriness or insomnia if the extract is not decaffeinated, constipation. This is educational information; check with a healthcare professional before use.
How strong is the evidence for EGCG (Epigallocatechin Gallate)?
NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
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