Gonadotropin-releasing hormone (GnRH) is a hormone that plays a critical role in regulating the reproductive system in both males and females. GnRH medications, also known as GnRH agonists and GnRH antagonists, are medications that are used to treat a variety of conditions related to the reproductive system, such as endometriosis, infertility, and certain types of cancer.

GnRH agonists mimic the effects of GnRH in the body, causing an initial stimulation of the pituitary gland followed by a decrease in GnRH production, leading to a decrease in the production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which play a critical role in regulating ovulation and sperm production. This decrease in LH and FSH production can have a number of therapeutic effects, including reducing the growth of endometriosis and certain types of cancer.

GnRH antagonists, on the other hand, work by blocking the effects of GnRH in the body, leading to a decrease in LH and FSH production. This can be useful in the treatment of infertility, as it can help to regulate ovulation and prevent premature ovulation during in vitro fertilization (IVF) procedures.

Examples of GnRH agonists include leuprolide (Lupron), leuprorelin (Prostap) and goserelin (Zoladex). GnRH antagonists include cetrorelix (Cetrotide) and degarelix (Firmagon).

Here are some references for further reading:

• Balen, A. H. (2010). Gonadotrophin-releasing hormone (GnRH) agonists and antagonists. Best Practice & Research Clinical Obstetrics & Gynaecology, 24(2), 137-147.
• Walschots, R. A., & Laven, J. S. E. (2011). GnRH agonists and antagonists in reproductive medicine. Reproductive Biology and Endocrinology, 9, 140.
• National Cancer Institute. (2021). GnRH Agonists for Cancer Treatment. Retrieved from https://www.cancer.gov/about-cancer/treatment/drugs/gnrh-agonists.