Supplements
green tea causes liver injury
In plain terms: Is green tea bad for your liver?
Part of: 🧪 Green tea
Brewed green tea is safe. The risk is with concentrated green-tea-EXTRACT supplements — especially high doses on an empty stomach — which can, rarely, cause serious liver injury (regulators added warning labels, and some people are genetically more susceptible). Drink the tea; be cautious with the pills.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
A real safety signal — but scoped tightly. Concentrated, high-dose green tea EXTRACT supplements (especially taken on an empty stomach) can cause idiosyncratic liver injury; the USP added cautionary labeling, an RCT was halted for liver-enzyme rises, and genetic susceptibility (COMT/UGT) raises risk. **Brewed green tea as a beverage is considered safe** — the concern is the concentrated pills.
The evidence (11)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Zheng EX et al. 2016 · Drug Saf | observational | supports | high | DILIN prospective registry: 6 RUCAM-adjudicated liver-injury cases from GTE weight-loss products (extract, not beverage). |
| Patel SS et al. 2013 · World J Gastroenterol | observational | supports | low | Case report: adolescent on a weight-loss GTE product - biopsy-confirmed acute hepatocellular injury / impending liver failure. |
| Ballotin VR et al. 2021 · World J Clin Cases | meta-analysis | supports | high | Systematic review/meta of herb-induced liver injury: green tea extract among top implicated botanicals (hepatocellular pattern). |
| Sarma DN et al. 2008 · Drug Saf | observational | supports | moderate | Original USP review (216 case reports): concentrated extract on an empty stomach more likely linked to liver injury than fed-state - prompted cautionary labeling. |
| Oketch-Rabah HA et al. 2020 · Toxicol Rep | observational | supports | high | USP comprehensive review: hepatotoxicity linked to bolus-dose/fasted concentrated EGCG (case reports 140-1000 mg/d), hepatocellular pattern, genetic susceptibility - concentrated EXTRACT, not brewed tea. |
| Acosta L et al. 2022 · J Diet Suppl | RCT | supports | moderate | Minnesota Green Tea Trial (n=1,075, 843 mg/d EGCG x12 mo): COMT/UGT genotype-dependent ALT/AST elevations - genetic susceptibility to extract hepatotoxicity. |
| Nederveen JP et al. 2023 · Nutrients | RCT | tested-null | moderate | RCT: multi-ingredient supplement incl. 500 mg GTE x12 wk - ALT/AST IMPROVED vs placebo, no hepatotoxic signal (GTE co-administered - confounded). |
| Lovera J et al. 2015 · J Neurol Sci | RCT | supports | moderate | Phase II RCT Polyphenon E (800 mg/d EGCG) in MS: halted early after 5/7 treated developed abnormal liver enzymes - high-dose extract can cause serious hepatotoxicity. |
| Hu J et al. 2018 · Regul Toxicol Pharmacol | meta-analysis | mixed | moderate | Systematic review 159 trials: hepatic adverse events only with concentrated bolus catechins, NOT beverage/with-food; safe bolus intake ~338 mg EGCG/d (704 mg/d as beverage). |
| Isomura T et al. 2016 · Eur J Clin Nutr | meta-analysis | tested-null | moderate | Meta 34 RCTs: liver-related adverse events (mild enzyme rises) rare, not significantly different from placebo (OR 2.1, CI 0.5-9.8). |
| He L et al. 2025 · Cancer Prev Res | RCT | tested-null | high | Phase I dose-escalation (cirrhosis, Polyphenon E 400-2000 mg/d x24 wk): well-tolerated to 1600 mg, no serious hepatotoxicity reached. |
Disagree, or know a study we missed?
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.