Glutathione for Liver Health

Verdict: Unproven for liver health

There is not enough good evidence to show that oral glutathione protects or improves general liver health. The only positive findings come from small, uncontrolled studies, while the single well-designed trial found no benefit.

U ⚫ U Unverified Insufficient Evidence

🔬Why this grade7-layer evidence engine

The favorable signals are all uncontrolled. A 2017 open-label, single-arm pilot in 34 people with fatty liver (PMID 28789631) and a 2025 literature review pooling 3 studies in 109 people (PMID 40149620) reported lower ALT on roughly 300 mg/day, but neither used a comparison group, so the improvement cannot be separated from concurrent diet and lifestyle changes or the natural course of the disease. Both sets of authors explicitly called for large randomized trials before any clinical recommendation.

The one rigorous test was negative. A 2020 double-blind randomized controlled trial in 61 cirrhosis patients (PMID 32635181) found that oral glutathione 500 mg/day had no significant effect on oxidative stress or antioxidant capacity over 12 weeks. Conventional oral glutathione is also a peptide that is largely broken down in the gut, which undercuts the rationale for raising liver glutathione by mouth.

Regulators and clinics offer no support for this use. The FDA has never approved glutathione for these purposes and has warned against injectable compounding, and UK authorities classify unlicensed IV glutathione as dangerous; major centers (Mayo, Cleveland Clinic, Harvard, NIH ODS) and liver societies do not endorse it. Note that intravenous N-acetylcysteine, the glutathione precursor, does help in acute liver failure (PMID 35371352), but that is a different drug and route and should not be read as evidence for oral glutathione supplements.

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable
Raw score 0.46
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
U · Insufficient Evidence
Confidence
70%
Broadly consistent
Evidence level
E3
Single high-quality meta-analysis

How strongly each layer supports this effect

lower = less supportive
L11 AI re-checkIndependent read
0.20
L2 PubMedPrimary literature
0.45
L3 MechanismPlausibility
0.45
L1 ExamineGlobal benchmark
0.50
L5 Clinical bodiesAuthoritative stance
0.55
Against Mixed Supports
View the full decision path (audit trail)
  1. compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.455
  2. tier_from_score — 依分數區間映射至 tier letter
  3. apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
  4. tier_strict_requirement_check — | C→U 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
  5. detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
  6. decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (4)L2 · primary research & systematic reviews

A Literature Review of Glutathione Therapy in Ameliorating Hepatic Dysfunction in Non-Alcoholic Fatty Liver Disease
PMID: 40149620 2025 Other n = 109
Finding: Across 3 studies (109 participants) oral glutathione showed consistent improvements in ALT and reductions in oxidative stress markers, but the authors stress that small sample sizes, inconsistent protocols and absence of RCTs limit generalizability; large-scale RCTs are needed before clinical recommendation.
🟠 Limited quality Effect size: Qualitative ALT improvement only; no pooled effect size (not a meta-analysis)
View on PubMed
Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study
PMID: 28789631 2017 RCT (open-label) n = 34
Finding: In 29 completers ALT decreased significantly after 4 months of oral glutathione; triglycerides, non-esterified fatty acids and ferritin also fell, and controlled attenuation parameter improved in ALT responders. Authors explicitly state large-scale clinical trials are needed to verify efficacy.
🟠 Limited quality Effect size: Significant ALT reduction; magnitude not controlled (no comparator arm)
View on PubMed
Impact of Glutathione and Vitamin B-6 in Cirrhosis Patients: A Randomized Controlled Trial and Follow-Up Study
PMID: 32635181 2020 RCT (double-blind) n = 61
Finding: Although reduced glutathione and related enzyme activity correlated with cirrhosis severity, oral glutathione and/or vitamin B-6 supplementation had NO significant effect on reducing oxidative stress or increasing antioxidant capacity over 12 weeks.
Government Effect size: Null — no significant between-group difference
View on PubMed
N-acetylcysteine in non-acetaminophen-induced acute liver failure: a systematic review and meta-analysis of prospective studies
PMID: 35371352 2022 統合分析
Finding: N-acetylcysteine (the glutathione precursor) was associated with improved outcomes in non-acetaminophen acute liver failure; for acetaminophen-induced liver failure NAC has been standard of care since the 1970s. Note this concerns the precursor NAC and intravenous use, not oral glutathione for general liver health.
Effect size: Improved transplant-free survival (precursor NAC, IV)
View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L4a US FDA
Against
FDA warns compounders not to use glutathione L-reduced powder distributed by Letco Medical to compound sterile injectable drugs for patients. The L-glutathione powder was labeled with 'Caution: Dietary Supplement' and should not have been used to compound sterile injectable drugs. source↗
L4b EU EFSA
Against
L4d TW TFDA / 衛福部
Cautious
由圓酵母(Torula yeast)發酵製成之食品原料穀胱甘肽,其每日食用限量為二百五十毫克,且應標示「對穀胱甘肽過敏者、孕婦、哺乳婦女及嬰幼兒應避免食用」之警語字樣。 source↗
L5c Cleveland Clinic
Neutral
L5e Specialty Society (condition-mapped)
Not addressed
PMID 100% verifiedevery citation checked via NCBI Entrez
🔬4 PubMed studiesindependently re-checked by multiple sub-agents
engine_version: v1.0 claim_id: CLM-COND-liver-health-INT-glutathione-001 繁體中文版 →