GnRH, short for gonadotropin-releasing hormone, is released by the part of the brain known as the hypothalamus. At the beginning of the menstual cycle, the hypothalamus releases GnRH. The GnRH then stimulates a different part of the brain, the pituitary gland, to produce two hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
FSH is the hormone that triggers the development of immature eggs in the ovary, while LH eventually triggers the release of the egg. Read more about ovulation here.
Source:
Medications for Inducing Ovulation: A Guide for Patients. American Society of Reproductive Medicine. Accessed February 3, 2008. http://asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/ovulation_drugs.pdf
