Effect of silymarin on hepatotoxicity in cancer patients undergoing chemotherapy: a systematic review and meta-analysis

Chemotherapy-induced hepatotoxicity frequently occurs in cancer patients and negatively impacts treatment adherence, dose management, and prognosis. Silymarin possesses general hepatoprotective properties. However, clinical evidence regarding its efficacy against chemotherapy-induced liver injury remains inconclusive. This systematic review and meta-analysis aimed to determine the overall effect of silymarin on hepatotoxicity in cancer patients undergoing chemotherapy. An ultimate literature search of Scopus, Medline, Web of Science, Cochrane Library, and Google Scholar was performed up to January 2026. Randomized clinical trials (RCTs) evaluating silymarin’s effect on liver toxicity in cancer patients receiving chemotherapy were considered eligible. Primary outcomes included Aspartate Aminotransferase (AST), Alanine Transaminase (ALT), Alkaline Phosphatase (ALP), and Total Bilirubin (TB). A random-effects model was employed to compute weighted mean difference (WMD) and 95% confidence interval (CI). Six RCTs were enrolled in this research. Silymarin supplementation significantly reduced AST levels (WMD: -7.34 IU/L, 95% CI: [-14.00, -0.69]) compared to controls. It also significantly decreased ALT levels (WMD: -6.54 IU/L, 95% CI: [-12.56, -0.43]). However, silymarin did not significantly alter ALP or TB concentrations. Subgroup analyses stated hepatoprotective effects on AST, ALT, and TB were most prominent with high-dose (> 150 mg/day) and long-term (≥ 60 days) supplementation. Silymarin may provide a significant hepatoprotective effect by lowering serum AST and ALT in cancer patients undergoing chemotherapy. On the other hand, it does not significantly affect ALP or TB. High-dose, long-term regimens demonstrated the greatest therapeutic efficacy. Further robust trials are needed to confirm these findings and elucidate underlying mechanisms. Not applicable.