Green Tea (EGCG)
Updated: 2025-10-07
Overview
Green tea (Camellia sinensis) is one of the richest sources of catechins, especially EGCG (epigallocatechin gallate) — a powerful antioxidant known for its effects on cellular longevity, cardiovascular health, and mental alertness.
The combination of EGCG + caffeine + L-theanine provides a balanced energy boost, ideal for focused attention without jitteriness.
It also naturally supports metabolism and weight management.
What the Evidence Shows
| Domain | Evidence Level | Observed Effects |
|---|---|---|
| Antioxidant & inflammation | High | Reduces oxidative stress and improves inflammatory markers. |
| Cardiovascular health | Moderate to high | Lowers LDL cholesterol and slightly reduces blood pressure. |
| Metabolism & weight | Moderate | Slight increase in energy expenditure and fat oxidation. |
| Alertness & cognition | Moderate | Improves concentration via caffeine + L-theanine synergy. |
Overall level: High for antioxidant effects; moderate to high for metabolism and alertness.
Mechanism of Action
- EGCG activates the enzyme AMPK, regulating cellular metabolism → ↑ fat oxidation.
- Neutralizes free radicals → protects DNA and cell membranes.
- Promotes endothelial vasodilation via the NO/eNOS pathway → improved blood flow.
- Caffeine + L-theanine: gentle stimulation of the nervous system → sustained alertness without anxiety.
💊 Dosage & Forms
| Form | Typical Dose | Approx. EGCG | Timing |
|---|---|---|---|
| Infusion | 2–3 cups/day | 200–300 mg total | Morning / early afternoon |
| Standardized extract | 300–500 mg/day | 50–90% EGCG | With meals |
| Matcha (whole powder) | 1–2 g/day | 100–150 mg EGCG | As a beverage |
💡 Tip: Consume with vitamin C (e.g., lemon juice) to increase catechin absorption.
Useful Synergies
| Combination | Main Effect |
|---|---|
| Green tea + L-theanine | Calm focus, reduced stress. |
| Green tea + Curcumin | Synergistic antioxidant action. |
| Green tea + Moderate caffeine | Controlled metabolic boost. |
| Green tea + Chromium / CLA | Weight management support. |
🟢 Proven Benefits
- Reduces oxidative stress and supports cardiovascular health.
- Enhances focus and alertness.
- Stimulates energy metabolism.
- Promotes long-term cellular protection.
🟡 Still Under Study
- True weight-loss effect remains modest.
- EGCG content and efficacy vary by preparation.
- Rare liver risks with high-dose extracts.
⚠️ Risks & Interactions
- Consult a healthcare professional if you have liver conditions, are pregnant/breastfeeding, or take stimulants.
- Highly concentrated extracts may be hepatotoxic at high doses.
- May potentiate the effects of caffeine, anticoagulants, or hypoglycemic drugs.
- May reduce the absorption of non-heme iron if consumed in excess.
✅ Quality Tips
- Choose organic green teas rich in EGCG (Sencha, Matcha, Gyokuro).
- Avoid extracts exceeding 800 mg/day of EGCG.
- Brew at ≤80°C to preserve catechins.
- Avoid drinking tea immediately after iron-rich meals.
Sources
- https://ods.od.nih.gov/
- https://www.canada.ca/en/health-canada.html
- https://pubmed.ncbi.nlm.nih.gov/34101960/
- https://examine.com/supplements/green-tea-extract/
- PubMed (34101960) — Meta-analysis on EGCG & cardiovascular health
- Examine.com — Green Tea Extract Overview
- NIH/ODS — Green Tea and Catechins
- Health Canada — Natural Health Products
⚠️ Educational information. Always seek professional advice.