A kind of fertility drug, GnRH agonists are artificial hormones that mimic the body’s natural hormone gonadotropin-releasing hormone (GnRH). A GnRH agonist first leads to a rapid increase in the production of the hormones FSH and LH. However, after this brief increase, the pituitary gland stops producing the hormones, preventing ovulation.
Used along with gonadotropins, GnRH agonists are usually part of IVF treatment. They are used to prevent natural ovulation. Instead, the fertility doctor will artificially stimulate ovulation with other fertility drugs, in a controlled manner known as superovulation. The drug also prevents the natural LH surge, which could lead to the eggs ovulating before they can be retrieved from the ovaries. (If the eggs are ovulated before they are retrieved, they get “lost” inside the pelvic cavity and cannot be used for IVF treatment.)
Some common GnRH agnosist include the medications Lupron, Zoladex, and Synarel. They are all injectables.
Source:
Medications for Inducing Ovulation: A Guide for Patients. American Society of Reproductive Medicine. Accessed February 3, 2008. http://www.asrm.org/Patients/patientbooklets/ovulation_drugs.pdf
