Green Tea Extract (EGCG)
Green tea's headline compound. High doses on an empty stomach have caused rare liver injury.
EGCG (epigallocatechin gallate) is the most active catechin in green tea, studied for antioxidant activity and a modest effect on fat oxidation, particularly when combined with caffeine. Standardised extracts typically list 45-50% EGCG content, with European Food Safety Authority guidance keeping the daily supplemental total below 800mg — higher doses taken on an empty stomach have been linked to rare cases of liver injury, which is why taking green tea extract with food is the sensible default. Isolated EGCG powders exist for research use, and matcha provides catechins in a whole-leaf form at much lower doses per serving than a concentrated extract. The compound has a natural morning bias, since its native drink is tea.
Forms and bioavailability
Not all forms are absorbed equally. The form on your supplement label affects how much your body can actually use.
| Form | Absorption | With food | Timing | Evidence |
|---|---|---|---|---|
| standardised green tea extract (50% EGCG) | Typical | Either | Morning | Strong |
| matcha powder | Lower | Either | Morning | Possible |
| EGCG isolate | Typical | Either | Morning | Likely |
| green tea catechin complex | Typical | With food | Morning | Possible |
How it pairs with other supplements
Works well with
EGCG inhibits catecholamine breakdown while caffeine stimulates release; combined effect on fat oxidation exceeds either alone (Hursel 2009).
Stack Almanac tracks your EGCG total across every source — a standardised extract, a matcha habit, and any caffeine paired with them are easier to see side by side than in a supplements drawer.
Track your Green Tea Extract (EGCG) in Stack Almanac
Last reviewed: 2026-07-22. Reference values are adult-general RDAs. Individual needs may vary. This page is for informational purposes only and is not a substitute for professional medical advice.