Pharmacology: Clomiphene citrate possesses both estrogenic and anti-estrogenic effects, however, the exact mechanism of action in the induction of ovulation on anovulatory women has not been determined. It stimulates the release of gonadotropin pituitary, follicle-stimulating hormone (FSH) and luteinising hormone (LH), which cause the development and maturation of ovarian follicle, ovulation and development and functionalisation of the corpus luteum.
The release of gonadotropin may result from direct stimulation of the hypothalamic-pituitary axis or because of the diminution of oestrogen inhibition effect to hypothalamic-pituitary axis by competing with endogenous oestrogen from uterus, pituitary or hypothalamus. Clomiphene citrate may also directly influence the biosynthesis of ovarian hormones.
Clomiphene citrate has no progestational, androgenic or antiandrogenic effects and it does not interfere with pituitary-adrenal or pituitary-thyroid functions.