Silymarin, an extract from the seeds of the milk thistle plant (Silybum marianum), has a long history of use in traditional medicine for liver ailments. However, its use for supporting or treating fatty liver disease (non-alcoholic fatty liver disease, NAFLD) is increasingly supported by scientific research. Silymarin exhibits antioxidant, anti-inflammatory, and antifibrotic properties, which are believed to protect liver cells from damage, reduce inflammation, and slow the progression of liver fibrosis. Several randomized controlled trials and meta-analyses suggest that silymarin supplementation can improve liver enzyme levels (e.g., ALT, AST) in patients with NAFLD, indicating potential benefits for liver function. These studies also report improvements in markers of oxidative stress and, in some cases, liver histology. However, the magnitude of benefit is typically modest, and not all studies show consistent results. The evidence base is limited by small sample sizes, short study durations, and variability in silymarin formulations and dosages. Major clinical guidelines do not universally recommend silymarin for NAFLD due to these limitations, but its favorable safety profile and some positive findings have led to its continued use as a supportive therapy. In summary, while silymarin is not a cure for fatty liver disease, there is moderate scientific evidence supporting its adjunctive use, especially for improving biochemical markers of liver injury.