Introduction: Enhancement of testosterone levels or its improper and arbitrary usage can disrupt fertility. Today, application of medicinal herbs is considered to treat hormonal disorders and infertility. In the present study, the effects of hydro-alcoholic extract of Withania coagulans (WCE) on sperm count and viability, gonadosomatic index, malondialdehyde(MDA) level and total antioxidant capacity(TAC) were investigated in rats’ testis following testosterone injection.
 
Materials & methods: In the current experimental study, 48 male Wistar rats were divided into 6 groups (n = 8). Control, Sham, Testosterone propionate (TP), and 3 TP treated with WCE (250, 500, and 1000 mg/kg/day). TP 3 mg/kg/body weight was injected subcutaneously and vehicle or WCE was administrated by oral gavage for 4 weeks. At the end of the gonadosomatic index, sperm count and viability, MDA and TAC level were measured.
 
Findings: The results showed a significant decrease in gonadosomatic index, sperm count, sperm viability and TAC level and an increase in MDA level in TP group compared to that of the control group (P<0.001). WCE improved the sperm qualitative parameters and TAC significantly, and decreased MDA level in the treated groups as dose-dependent, (P < 0.05).
 
Discussion & conclusion: As demonstrated by our findings, Withania coagulans extract seems to improve the fertility parameters, and could be useful to treat infertility problems; although, more research needs to be accomplished.