International Journal of Preventive Medicine (Int J Prev Med)2008-78021442023050828022802ENDepartment of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, IsfahanDepartment of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy, Isfahan University of Medical Sciences, Isfahan & Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, IsfahanDepartment of Infectious Diseases, School of Medicine, Isfahan University of Medical Sciences, Isfahan & Nosocomial Infections Research Center, Isfahan University of Medical Sciences, IsfahanDepartment of Epidemiology, Erasmus Medical Center, Rotterdam20230508Background: Several animal studies have shown the protective effect of silymarin (the extract of Silybum marianum seeds) against anti‑tuberculosis drug‑induced hepatotoxicity (ATDH). However, the knowledge of ATDH of silymarin in humans is scarce. In this study, we aimed to clinically evaluate it. Methods: During this randomized controlled clinical trial, 36 new cases of tuberculosis (TB) were enrolled to receive either silymarin 150 mg twice daily for two weeks along with a standard anti‑TB therapeutic regimen (experimental group; n = 16) or standard anti‑TB therapeutic regimen alone (control group; n = 21). Liver function tests (serum AST, ALT, ALP, and total bilirubin) at the end of weeks 1 and 2 as well as the rate of ATDH during the study were determined and compared between the groups. Results: No significant differences between the experimental and control groups were observed at the end of the first week regarding liver function tests; However, at the end of the second week, the mean serum levels of AST (P = 0.03) and ALP (P = 0.04) were significantly lower in the experimental group. ALT (P = 0.016) and ALP (P = 0.027) levels in the experimental group significantly decreased during the study, while the changes in the control group were not significant. Two patients in the control group (9.5%) developed ATDH, while no one in the experimental group manifested this adverse effect. Conclusions: Our study suggests that silymarin use has the potential for the reduction of anti‑TB drug‑induced hepatotoxicity.http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2802http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2802/717718643