Its mode of action is based on its similarity to estrogens. That is why clomiphene citrate binds to estrogen receptors found in the hypothalamus, competing for those receptors with estrogen and thus reducing their action. This binding promotes the stimulation of and secretion of GnRH, which in turn produces the release of FSH and LH gonadotropins.
When treatment with clomiphene citrate is suppressed, a decrease in GnRH is produced, which causes estradiol to increase 2 or 3 times its normal amount. The increase in estradiol stimulates the LH peak that will trigger ovulation. That is why its uncontrolled use can generate the risk of multiple gestation.
Due to its mode of action it is widely used in ovulation induction treatments for patients with ovulation problems, such as Polycystic Ovary Syndrome.