Enclomiphene

Enclomiphene acts as an estrogen receptor antagonist in the hypothalamus and pituitary gland, blocking estrogen's negative feedback on GnRH and gonadotropin secretion. By removing this inhibitory signal, it increases pulsatile GnRH release from the hypothalamus, which in turn drives increased LH and FSH secretion from the pituitary. Elevated LH stimulates Leydig cell testosterone production, while increased FSH supports Sertoli cell function and spermatogenesis. The result is elevated endogenous testosterone with maintained or improved sperm production — in contrast to exogenous testosterone which suppresses both. Enclomiphene is the active isomer of clomiphene, separated to remove the less desirable zuclomiphene isomer that has longer half-life and may contribute to side effects.