Clomifene or clomiphene is a selective estrogen receptor modulator (SERM), used mainly in female infertility due to anovulation (e.g. due to polycystic ovary syndrome). In some countries, it is also registered for use in men. Clomiphene citrate is marketed under various trade names including Clomid, Serophene, Milophene, etc.

Clomifene acts by inhibiting the action of estrogen on the gonadotrope cells in the anterior pituitary gland. "Sensing" low estrogen levels, follicle-stimulating hormone (FSH) release is increased, leading to a higher rate of ovulation and hence pregnancy.

Clomifene can lead to multiple ovulation, and hence increasing the chance of twins. In comparison to purified FSH, the rate of ovarian hyperstimulation syndrome is low. There may be an increased risk of ovarian cancer, and weight gain.

Clomifene is commonly used by male anabolic steroid users to bind the estrogen receptors in their bodies, thereby blocking the effects of estrogen, ie gynecomastia. It also restores the bodies natural production of testosterone. It is commonly used as a "recovery drug" and taken toward the end of a steroid cycle.

Before taking any prescription medicine, it is important that you consult your doctor!