Positives

• Some Long COVID patients report that green tea extract combined with black pepper for absorption helped break fatigue cycles Reddit.

Negatives

• NIH LiverTox classifies high-dose green tea extract as a documented cause of acute liver injury, with the European Food Safety Authority concluding doses above 800 mg EGCG/day raise liver damage risk; injury is idiosyncratic and linked to HLA-B*35:01. NIH.
• PMC research shows hepatotoxicity risk from high-dose green tea extract is partly genetic, with COMT and UGT1A4 variants influencing susceptibility; roughly 5% of women on a year-long EGCG supplementation course commonly develop liver enzyme elevations. PMC.
• Patients on EGCG can see iron absorption blunted, blood pressure and heart rate rise at high concentrations, and liver stress. Frontiers.

Hurdles & Side Effects

• Many patients note difficulty determining if EGCG provides specific benefit compared to other supplements Reddit.
• ME/CFS users report taking high doses up to 2000mg daily without noticeable energy improvements Reddit.
• Some patients avoid EGCG due to genetic biomarker reports suggesting personal contraindications Reddit.