Gonadotropin releasing hormone (GnRH) is secreted by the hypothalamus and results in release of both luteinizing hormone (LH) and follicle stimulating hormone (FSH). In patients with hypothalamic or pituitary disorders, serum levels of LH and FSH may be decreased. Measurement of LH and FSH is done before and after administration of GnRH to demonstrate pituitary release of gonadotropins.
