Research synthesisModerate evidenceMixed effect size6 studies · 4 beneficial · 2 neutral · 0 harmful
Across 6 studies (4 beneficial, 2 neutral), thistle (silymarin) shows mixed evidence for reducing alanine aminotransferase (ALT) levels, with effect sizes ranging from small to large. The strongest evidence comes from meta-analyses in clinical populations with liver conditions (NAFLD, alcoholic liver disease, anti-tuberculosis drug-induced liver injury). Median study duration was approximately 15 weeks across the two studies that reported it, but dose information is limited.
- Studied populations: Clinical populations with liver-related conditions (non-alcoholic fatty liver disease, alcoholic liver disease, anti-tuberculosis drug-induced liver injury) and healthy adults in one study
Caveats: The evidence is dominated by meta-analyses showing beneficial effects, but one RCT in acute hepatitis found no significant effect and a low-quality review on iron overload did not show benefit from related plant antioxidants. Study durations were inconsistently reported; the median of 104 days in two studies suggests longer-term use may be needed. Dose information is sparse—only one neutral RCT reported a specific dose (140 mg three times daily).
Generated Jul 15, 2026