Green tea extract
A concentrated extract from tea leaves (Camellia sinensis) standardized for catechins like EGCG; used for flavor, antioxidant protection, and marketed health benefits.
Should I eat Green tea extract?
Green tea extract is a concentrated source of tea antioxidants that’s generally safe in foods and tea-like amounts, but high‑dose supplements can stress the liver. Check labels for EGCG content and avoid pushing your daily intake into the high range.
Summary
This extract concentrates catechins such as EGCG from tea leaves. Most safety concerns come from supplemental, high‑dose products rather than brewed tea. Trials link about 800 mg/day of EGCG to elevated liver enzymes, and rare injuries have occurred at lower intakes with certain ethanolic extracts. The EU restricts EGCG per portion and requires label warnings to help consumers manage intake. If you use products with green tea extract, add up EGCG from all sources and stay well below high supplemental doses.
Key Research Benefits
Source of catechin antioxidants
Green tea extract provides catechins such as EGCG that act as antioxidants in the body and in foods.
Helps protect fats in foods
Specialized forms of green tea catechins are recognized for use as antioxidants in foods, helping slow rancidity.
Key Research Risks
Liver enzyme elevations at high doses
Supplements delivering around 800 mg/day of EGCG have increased liver enzymes in trials; risk is mainly tied to concentrated extracts, not brewed tea.
Rare idiosyncratic liver injury
Isolated cases of liver injury have occurred at lower intakes with certain ethanolic extracts, so stop use and seek care if you develop dark urine, jaundice, or severe fatigue.
Stay within labeled limits
EU rules cap EGCG at <800 mg per portion and require warnings; adding multiple products can push total daily intake too high.
Overview
What is it?
Why is it used?
Origin
Green tea comes from the same plant as black and oolong tea but is heated early to prevent fermentation, preserving its fresh, grassy flavor and catechins. It has been brewed for over a thousand years in China and Japan and popularized globally in the 20th century as both a drink and, more recently, as concentrated extracts for foods and supplements.
Process: Aqueous/ethanol extraction, concentrate & dry
Steps
Chemicals
Research & Safety
Potential Concerns
The main concern is liver stress from high doses of EGCG found in concentrated supplements. Trials show increased liver enzymes around 800 mg/day of EGCG, and rare cases of injury have occurred at lower intakes with certain ethanolic extracts. The EU now caps EGCG at under 800 mg per portion and requires label warnings, which helps consumers avoid excess. If you choose a product with green tea extract, add up EGCG from all sources and stop use if you develop symptoms of liver problems (e.g., dark urine, jaundice, unusual fatigue). Brewed tea at typical intakes is generally not a concern.
Potential Benefits
Green tea extract supplies polyphenols (especially EGCG) that act as antioxidants. These compounds can neutralize free radicals and may help protect fats in foods from oxidation, which is why they are used as food antioxidants. While some studies report modest improvements in markers like cholesterol, blood pressure, or blood sugar with green tea catechins, results vary by product, dose, and individual. Benefits, if any, are more likely at food-like intakes and when part of an overall healthy pattern.
Digestive Effects
Most people tolerate tea-like intakes well. At higher supplemental doses, some experience nausea or abdominal discomfort; these effects tend to resolve after stopping. Products that contain caffeine can also cause jitteriness or sleep disturbance in sensitive people. If you have reflux (GERD), concentrated extracts may worsen heartburn. Starting low, avoiding use on an empty stomach, and choosing decaffeinated extracts (if caffeine-sensitive) may reduce symptoms.
Limit Consumption
Infants and young children should not consume supplemental EGCG; these products are not intended for them. People with existing liver disease or a history of unexplained hepatitis should avoid high‑dose green tea extracts and consult a clinician before use. Pregnant or breastfeeding individuals should be cautious with concentrated extracts due to limited data at high EGCG doses and potential caffeine exposure. Those taking medicines with known liver risks should check with a healthcare professional before using concentrated green tea extract.
Fact Sheet
Regulatory Status
ESG & Sustainability
Allergens and Diet
Natural Alternatives
Brewed green tea
Rosemary extract
Cocoa extract (polyphenols)
Citations
Scientific opinion on the safety of green tea catechins
2018-04-18Younes M., Aggett P., Aguilar F., et al. • EFSA Journal
Commission Regulation (EU) 2022/2340 — green tea extracts containing EGCG
2022-11-30European Commission • EUR-Lex
EFSA green tea catechins page/summary
2018-04-18EFSA Panel on ANS • EFSA
Statement on the hepatotoxicity of green tea catechins
2024-12-05Committee on Toxicity • UK FSA (COT)
GRN 259 — Catechins from green tea extract
2008-09-08FDA • FDA (CFSAN GRAS Notices)
GRAS Notice GRN 772 — Palmitoylated green tea catechins (Agency Response)
2018-12-13FDA • FDA
List of Permitted Supplemental Ingredients — Green Tea Extract
2024-01-11Health Canada • Health Canada