Brief Summary: The goal of this study is to learn about the role of kisspeptin in the reproductive system. Kisspeptin is a naturally occurring hormone in humans that causes the release of other hormones, including gonadotropin-releasing hormone (GnRH) in the body.

Detailed Description: The reproductive hormone GnRH is essential for normal reproductive function. People with idiopathic hypogonadotropic hypogonadism (IHH), hyperprolactinemia, and polycystic ovarian syndrome (PCOS) do not secrete or respond to GnRH in a normal way. In this study, investigators will give participants kisspeptin-a hormone that is naturally found in the human body and is known to be a powerful stimulus of GnRH secretion. They may also give participants GnRH to determine if participants will be able to fully respond to kisspeptin. The goal of this study is to use kisspeptin administration to probe the condition of GnRH neurons in people with various reproductive disorders to better understand the underlying reasons for the disorders. Investigators hope to gain new insights into GnRH neuronal function (or dysfunction) that will lead to better diagnostics in the future.