Research synthesisModerate evidenceMixed effect size9 studies · 5 beneficial · 4 neutral · 0 harmful
Across 9 studies, 5 reported beneficial effects of thistle (silymarin) on reducing aspartate aminotransferase (AST) levels, with effect sizes ranging from small to large, while 4 studies found neutral effects. The median study duration was 59 days, suggesting effects typically observed at 8-12 weeks. Most evidence comes from clinical populations with liver conditions (e.g., MASLD, NAFLD, ALD), and a common dose was 140 mg three times daily, though many studies did not specify dose.
- Effective dose range: 140 mg three times daily
- Studied populations: adults with metabolic dysfunction-associated steatotic liver disease (MASLD), non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and acute hepatitis
Caveats: Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Study durations varied widely (28 to 180 days), and several studies lacked dose or form details, limiting comparability.
Generated Jul 3, 2026