Confirmed diagnosis of HH with  Low testosterone or estradiol Low or low-normal gonadotropin levels Thyroid Stimulating Hormone (TSH) and prolactin within the reference range Absence of abnormal pituitary or hypothalamic findings on Magnetic Resonance Imaging (MRI) All other medical conditions stable and well controlled No prescription medications known to affect reproductive endocrine function for at least 2 months or for 5 half-lives of the drug (whichever is shorter) except for medications used to treat the subject's reproductive condition No history of a medication reaction requiring emergency medical care No opiate drug use No excessive alcohol consumption (<10 drinks/week) Not currently seeking fertility If applicable, able to undergo appropriate washout from hormone therapy Normal blood pressure (BP), (systolic BP < 140 mm Hg, diastolic < 90 mm Hg) White blood cell, platelet counts, and TSH between 90% of the lower limit and 110% of the upper limit of the reference range  Hemoglobin  Women: no less than 0.5 gm/dL below the lower limit of the reference range for normal women Men: on adequate testosterone replacement therapy: normal male reference range; off testosterone replacement therapy: no lower than 0.5 gm/dL below the lower limit of the reference range for normal women Blood urea nitrogen (BUN), creatinine, aspartate aminotransferase (AST), alanine transaminase (ALT) not elevated Negative urine drug screening panel  For women  Negative serum human chorionic gonadotropin (hCG) pregnancy test at the time of screening (additional urine pregnancy test will be conducted prior to drug administration) Not breastfeeding and not pregnant