The goal of this study is to develop novel treatments for patients with a condition called hypogonadotropic hypogonadism (HH) through the use of exogenous kisspeptin.

* Assignment: Each study subject will serve as their own control. The order of kisspeptin doses will be randomized within each set/exposure. * Delivery of Interventions: * Prior to the study visit, subjects will undergo a review of their medical history and screening laboratories. Subjects will also wear a gonadotropin releasing hormone (GnRH) pump prior to the inpatient study visit. * On the day of the inpatient study, the subjects will * Undergo q10 min blood sampling for 6 hours, * Receive kisspeptin intravenous (IV) boluses from hour 6 to hour 44 (20 boluses total), * Undergo q10 min blood samplings for another 6 hours, * Receive a single GnRH IV bolus at hour 51.