Silymarin, a flavonoid complex extracted from the seeds of Silybum marianum (milk thistle), has a long history of traditional use for liver disorders, but its use is also supported by scientific evidence. Silymarin is thought to exert hepatoprotective effects via antioxidant, anti-inflammatory, and antifibrotic mechanisms. Preclinical studies demonstrate that silymarin can protect hepatic cells from toxic insults (like alcohol, acetaminophen, or toxins such as amanitin) and reduce lipid peroxidation in liver tissue.

Clinical evidence, though mixed, suggests some benefit in chronic liver diseases. Several randomized controlled trials and meta-analyses have found that silymarin supplementation may lead to small but statistically significant reductions in liver enzyme levels (ALT, AST) in patients with chronic hepatitis or cirrhosis. However, effects on more meaningful clinical outcomes, such as mortality or progression to liver failure, remain unproven. Silymarin is generally well tolerated, with few serious adverse effects reported.

Major guidelines (e.g., AASLD, EASL) do not currently endorse silymarin for routine treatment of liver diseases due to insufficient evidence of clinical benefit. Nevertheless, its use as a supportive supplement for liver health is justified by both historical use and moderate scientific data, particularly for mild to moderate liver dysfunction. Ongoing research may further clarify its role in hepatic support.