Cetrorelix is a man-made hormone that blocks the effects of Gonadotropin Releasing Hormone (GnRH). GnRH controls another hormone that is called luteinizing hormone (LH), which is the hormone that starts ovulation during the menstrual cycle. When undergoing hormone treatment sometimes premature ovulation can occur, leading to eggs that are not ready for fertilization to be released. Cetrorelix does not allow the premature release of these eggs to occur. (en)
Cetrorelix binds to the gonadotropin releasing hormone receptor and acts as a potent inhibitor of gonadotropin secretion. It competes with natural GnRH for binding to membrane receptors on pituitary cells and thus controls the release of LH and FSH in a dose-dependent manner. (en)
Rapidly absorbed following subcutaneous injection. The mean absolute bioavailability following subcutaneous administration to healthy female subjects is 85%. (en)