en-clofert 50 (Androxal), in development by Repros Therapeutics Inc, is a non-steroidal estrogen receptor antagonist that promotes gonadotropin-dependent testosterone secretion by the testes.Enclomiphene 50 constitutes the trans-stereoisomer of clomiphene citrate, a drug that has been widely prescribed for several decades for the treatment of female ovulatory dysfunction.

In clinical trials conducted to date, enclomiphene 50 demonstrated significant efficacy in the physiological restoration of testosterone levels in males with secondary hypogonadism. The compound also exhibited an unanticipated favorable effect on fasting plasma glucose; this result has been accompanied by rapidly accumulating evidence from other researchers for a bidirectional relationship between low serum testosterone and obesity/metabolic syndrome (syndrome X) in men.