herb · for chronic fatigue
EGCG
Meant to raise heat production and prompt cells to build more energy machinery.
Say that in clinical terms
Promotes thermogenesis and catechin-mediated mitochondrial biogenesis, enhancing cellular energy production.
How strong is the research?
1 paper read.
Who was studied: All of it is sports research in trained athletes, not people with ongoing fatigue.
Searched PubMed, PMC, and Cochrane for any human trial of green tea extract or EGCG for chronic fatigue or ME/CFS. The published literature contains animal studies (mouse forced-swim fatigue models; selenium-polysaccharide CFS rat models) but no human RCTs targeting chronic fatigue as the primary outcome. One EGCG RCT in relapsing-remitting multiple sclerosis (25733633) measured muscle metabolism during exercise but was designed for MS, not CFS, and fatigue was not a primary endpoint. MEpedia and the Phoenix Rising patient forum confirm no established trial record for green tea extract in ME/CFS. The anti-fatigue PMC article (PMC5421434) is an animal study, not a human trial. Nothing in the
How much to take
daily
400–800 mg
Standardized to 50-90% EGCG. Take with vitamin C for enhanced absorption.
Before you take it
- EFSA (2018) Scientific Opinion found that EGCG doses ≥800 mg/day from food supplements produce statistically significant increases in serum transaminases; EU Regulation 2022/2340 restricts single-portion EGCG content to <800 mg. No NIH/IOM Tolerable Upper Intake Level (UL) has been established for EGCG as a supplement; EFSA's 800 mg/day threshold is the most specific regulatory benchmark available.
- Drug-induced liver injury (DILI): EFSA reviewed 78+ case reports of liver injury linked to green tea extract supplements; risk is elevated with fasted intake and at high doses. UK Committee on Toxicity (COT) has independently reviewed and corroborated this evidence.
- CYP3A4 and P-glycoprotein inhibition: EGCG may elevate plasma concentrations of statins (atorvastatin, simvastatin), calcineurin inhibitors (cyclosporine, tacrolimus), and some calcium channel blockers.
- Non-heme iron absorption inhibition: EGCG significantly reduces non-heme iron absorption; caution is warranted in iron-deficient individuals and those with anemia.
- Antibiotic interaction: EGCG chelates fluoroquinolones and may reduce beta-lactam and tetracycline absorption; doses should be separated by at least 2h before or 4-6h after antibiotic administration per NIH ODS guidance.
- Mild antiplatelet activity: additive bleeding risk with warfarin or direct oral anticoagulants (DOACs).
- Contraindicated at supplemental doses during pregnancy: high-dose EGCG inhibits dihydrofolate reductase, impairing folate metabolism.
- Variable caffeine content: many green tea extracts retain caffeine; may exacerbate anxiety, hypertension, or arrhythmia in sensitive individuals.
What we make of it
The source is a book chapter about sports performance.
The detail
What we cite is a chapter in a book on green tea and sport, not a pooled analysis. The mitochondria-building effect is established in rodents and has not been reproduced convincingly in people.