Weight Management
Green Tea Extract (EGCG)
Also known as: EGCG · Epigallocatechin gallate · Camellia sinensis extract
The most active catechin in green tea. Inhibits COMT (prolongs norepinephrine activity), increasing fat oxidation and thermogenesis. Synergistic with caffeine.
Effective Dose
400–800mg EGCG / day
per clinical evidence
Evidence Level
Moderate
Weight Management
Mechanism
COMT inhibition → catecholamine prolongation, AMPK activation, thermogenesis
primary action
Best For
Fat oxidation
Metabolism boost, Antioxidant, Cognitive health
This profile is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications.
What Is Green Tea Extract (EGCG)?
Epigallocatechin gallate (EGCG) is the primary catechin in green tea, responsible for most of its metabolic and health benefits. It inhibits catechol-O-methyltransferase (COMT) — the enzyme that breaks down catecholamines — prolonging norepinephrine signalling and thermogenesis. This synergises powerfully with caffeine, which blocks adenosine (allowing greater norepinephrine release).
How It Works: The Science
COMT methylates and inactivates norepinephrine (NE) and epinephrine. EGCG inhibition of COMT prolongs NE lifespan in the synapse, enhancing beta-adrenergic receptor stimulation of adipocyte lipolysis and thermogenesis (via uncoupling proteins). EGCG also activates AMPK, inhibits fatty acid synthase (FAS), and reduces NF-κB-driven inflammation.
Primary Mechanism
COMT inhibition → catecholamine prolongation, AMPK activation, thermogenesis
Evidence-Based Benefits
Dosage Guide
Effective Dose
400–800mg EGCG / day
400–800mg EGCG/day (or 3–4 cups of green tea providing ~100–200mg EGCG each). Supplements are more reliable for consistent dosing. Take with caffeine for synergistic thermogenic effect. Avoid taking on an empty stomach (hepatotoxicity risk at high doses).
Safety Profile & Side Effects
Hepatotoxicity has been reported with high-dose EGCG supplements (>800mg/day) on an empty stomach — always take with food. Certified safe at <800mg EGCG/day with food. Contains caffeine if not decaffeinated extract — account for total caffeine intake.
Who Should (and Shouldn't) Take It
Those in a fat loss phase wanting a modest but real thermogenic boost. Excellent synergy with caffeine. Also valuable as a daily antioxidant and cardiovascular protective supplement at lower doses.
Frequently Asked Questions
Related Ingredients
Medical Disclaimer
Ingredient profiles are for informational purposes only and do not constitute medical advice. Consult a qualified healthcare professional before starting any supplementation, especially if you have pre-existing conditions or take medications. Full disclaimer →