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Epigallocatechin Gallate (EGCG) — Frequently Asked Questions

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Frequently Asked Questions

Is green tea extract safe for the liver?

At moderate doses taken with food (200-500mg EGCG), green tea extract is generally safe. However, high doses (800mg+) taken on an empty stomach have caused liver injury in documented cases. The European Food Safety Authority recommends not exceeding 800mg EGCG daily from supplements. Always take green tea extract with food and avoid fasted dosing to minimize hepatotoxicity risk.

Is drinking green tea as effective as taking EGCG supplements?

A cup of green tea provides approximately 50-100mg EGCG. Drinking 3-5 cups daily delivers 150-500mg EGCG in a natural matrix with L-theanine and other catechins. This is comparable to standard supplement doses and may be safer due to slower absorption. However, supplements offer convenience and precise dosing. Matcha provides the highest EGCG per cup since you consume the whole leaf.

Does EGCG interfere with iron absorption?

Yes. EGCG chelates non-heme iron (plant-based and supplemental iron), reducing its absorption by up to 25%. If you have iron deficiency or take iron supplements, separate EGCG intake from iron-rich meals or supplements by at least 2 hours. This does not affect heme iron from meat sources.

Full Epigallocatechin Gallate (EGCG) Guide

References

  1. (). The anti-obesity effects of green tea in human intervention and basic molecular studies. European Journal of Clinical Nutrition. DOI
  2. (). Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan. JAMA. DOI
  3. (). Hepatotoxicity of green tea: an update. Archives of Toxicology. DOI