Green Tea Extract / EGCG

Camellia sinensis extract / epigallocatechin gallate (EGCG)

Human evidence for concentrated green tea extract and EGCG is still mixed. The clearest public signal is modest help with body weight or waist-related measures, but that does not prove meaningful fat loss. Cholesterol, blood pressure, blood sugar, and liver-marker findings remain too inconsistent or too thin for stronger benefit claims, while high-dose EGCG warrants extra liver-safety caution.

What the research says

Each row is a different health effect. A means the support looks strongest, B likely helpful, C mixed or modest, and — not enough human evidence yet.

C · Mixed or limited evidence
C
Weight, waist & body composition
Reviews and several trials suggest small reductions in body weight, waist size, or some body-composition measures, but results are inconsistent and not every study shows benefit. Small weight changes should not be sold as proven fat loss.
7 papers · 2 research reviews
— · Not enough human evidence yet
Cholesterol & blood fats
Some studies suggest modest improvement in LDL or triglycerides, but the supplement evidence currently shown on this page is limited and not consistent enough for a dependable cholesterol claim.
3 papers · 1 research review
Blood pressure & vascular function
A few trials report small blood-pressure or vascular-function improvements, but the evidence base is still too small and mixed for a dependable blood-pressure benefit claim.
4 papers · 1 research review
Liver markers & fatty liver context
The current human evidence does not show a clear supplement benefit for fatty liver or liver markers, and liver-enzyme changes should not be confused with proven liver-health improvement.
3 papers · 1 research review

Safety

Safety is graded separately from benefits. Even with a favorable safety label, these notes still matter if you take medication, are pregnant, or have a medical condition.

✓ Safe No clear harm signal in the human evidence reviewed.
Side effects and tolerability
Short-term studies do not show a strong overall side-effect signal, but stomach upset, nausea, or digestive discomfort can still happen, especially at higher EGCG exposures.
3 papers · 1 research review
Liver, fasting & medication cautions
High-dose EGCG-heavy extracts deserve extra caution, especially on an empty stomach or in people with liver concerns. Use extra care with blood thinners, stimulant-sensitive or caffeine-sensitive contexts, and blood pressure or blood sugar medicines.
2 papers

Quick facts

Dose, form and timing based on trials in the database.

Typical dose
300–843 mg/day of EGCG or catechin-rich green tea extract in many retained oral trials; some decaffeinated polyphenol studies used 400 mg/day
Best taken
Usually once or twice daily with food for several weeks to months. Avoid taking high-dose EGCG-heavy extracts on an empty stomach
Form
Most of the current human evidence uses capsules, tablets, or standardized extract products rather than brewed green tea. Decaffeinated extracts, EGCG-heavy products, and tea beverages should not be treated as interchangeable
Common side effects
Stomach upset, nausea, and other digestive discomfort, especially at higher doses
Medication cautions
Use extra caution with blood thinners, stimulant-sensitive or caffeine-sensitive contexts, blood pressure or blood sugar medicines, surgery, and pregnancy or breastfeeding
Big interpretation limit
Small shifts in weight, waist size, cholesterol, or lab markers do not prove fat loss, heart protection, or liver repair, and beverage-tea findings should not be merged with concentrated extract products

Quality-verified products

Products that pass third-party quality testing.

Product quality data coming soon
Product recommendations are being built from USP Verified, NSF Certified, and Labdoor test data. Products will only appear here after the supplement itself clears the evidence bar above — and only if the product passes third-party purity testing.

How we graded Green Tea Extract / EGCG

Grades come from 34 unique research papers indexed from PubMed — including 12 review-level papers and 19 randomized trials. Each supplement is graded by health effect using a certainty × effect matrix applied across PubMed evidence per health effect. Cochrane reviews and high-quality systematic reviews carry the most weight. From abstract-only data, "high certainty" is rare — most A grades come from moderate certainty plus consistent meaningful-positive evidence. See Methodology for full detail.

Read the full methodology →