Green Tea Extract (EGCG)

Evidence: ★★★☆☆ · Status: OTC Supplement

In plain English

Makes your natural fat-burning signal last longer. Real but small; watch high-dose liver effects.

How it works

EGCG inhibits catechol-O-methyltransferase (COMT), prolonging norepinephrine's fat-mobilising signal; synergistic with caffeine.

Molecular target & official sources

COMT (NCBI Gene) · EGCG (PubChem CID 65064)

Protocol

400–500 mg EGCG/day.

Watch out

Rare liver toxicity at high isolated doses — take with food.

Bottom line

Minor helper, not a driver.

Helps with: Lose Fat

The human evidence

Meta-analyses show a modest increase in fat oxidation and small weight loss, strongest when paired with caffeine and in non-habitual caffeine users. The effect is real but small.

Stacks with

Caffeine (synergistic thermogenesis).

Shares a pathway — often paired with: Caffeine, Modafinil / Armodafinil, Amphetamine (Adderall) / Lisdexamfetamine (Vyvanse), Methylphenidate (Ritalin).

Avoid combining with

High-dose extracts taken fasted carry a rare risk of liver injury — take with food and keep to sensible doses; whole brewed tea is safest.

Availability & where to buy

Available over the counter. Widely available OTC — e.g. iHerb (ships worldwide); in Singapore also Guardian, Watsons, GNC, Shopee / Lazada. Look for a third-party-tested / GMP mark and check the dose per serving. Cheap — brewed green tea costs almost nothing; standardised extract ~S$20–30/month.

How it works: the Monoamines pathway →

Used in these protocols

• Insulin Resistance
• Belly / Visceral Fat
• Fat Loss Plateau