Green tea contains vitamin K; may reduce warfarin effectiveness. Also EGCG alters CYP metabolism.
EGCG reduces nadolol absorption by 85% via OATP transporter inhibition
EGCG chelates non-heme iron; reduces absorption by 25-60%. Separate by 2+ hours.
Green tea extract contains caffeine; additive stimulation
EGCG may inhibit folate metabolism (dihydrofolate reductase inhibition)
EGCG inhibits CYP3A4 in vitro; clinical significance uncertain
EGCG directly inactivates bortezomib, AVOID
EFSA reviewed 21 cases of liver injury from green tea extract supplements (PMID: 29058885). Findings:
Not Prohibited
Reference identifiers on this page are being re-verified against PubMed. Some may not yet link to the paper named beside them.
, Hursel R et al. The effects of green tea on weight loss and weight maintenance: a meta-analysis.
, EFSA Panel. Scientific opinion on the safety of green tea catechins.
, Mazzanti G et al. Hepatotoxicity from green tea: a review of the literature.
, Kim YC et al. Green tea catechin-induced hepatotoxicity.
Independently graded against 178,763 indexed supplements and 757 reviewed supplement and medication pairs, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated: April 2026
Not medical advice. Based on published clinical research and systematic reviews.
Safety
Nadolol (beta-blocker)
Warfarin
Iron supplements
Stimulant medications (Adderall, Ritalin)
MAOIs
Timing Separation Rules
Educational information only. This is not medical advice. These statements have not been evaluated by the FDA. Talk to your prescriber before starting, stopping, or combining any supplement with prescription medication.