These medicines are often used for women who don’t ovulate regularly each month. Women who ovulate before the egg is ready can also use these medicines. Gn-RH analogs act on the pituitary gland to change when the body ovulates. These medicines are usually injected or given with a nasal spray.

These drugs may be used for the treatment of endometriosis and fibroids. They work by initially stimulating, then switching off ( down-regulating) the pituitary gland, and are administered intranasally or by injection. They thus induce a “menopausal” state, allowing the endometriosis and fibroids to shrink, since there is no further production of estrogens.

(Brand names: Lupron, Synarel, Zoladex, Antagon). GnRH analogs are synthetic hormones that have a continuous effect, unlike the normal 90-minute pulsations of GnRH. This blocks production of both LH and FSH. These analogs are commonly used along with gonadotrophin injections in IVF (in vitro fertilization) clinics. Since LH may cause release of eggs from the follicles before they are ready, GnRH analogs are used to prevent that from happening. Reported side effects include headaches, insomnia, and mood swings.

With Lupron, the reproductive endocrinologist has maximum control over the “endocrine events” occurring during the stimulation cycle thus maximizing the chance of successful egg retrieval and subsequent conception. Lupron also treats endometriosis by lowering the circulating levels of estrogen, which is required for endometrial tissue growth.