Kisspeptin Administration in the Adult

A. Healthy Subjects

All healthy subjects will meet the following criteria:

* normal puberty with respect to onset and pace,
* no chronic diseases,
* no difficulty with blood draws,
* no prescription medications for at least 2 months with the exception of seasonal allergy medications and hormone replacement therapy,
* no illicit drug use or excessive alcohol consumption (\< 10 drinks/week),
* no history of a medication reaction requiring emergency medical care,
* normal physical exam and laboratory studies within protocol reference ranges.

Additional criteria based on subject population:

1. Healthy Men:

   * between 21 and 40 years old,
   * normal erectile and ejaculatory function, no history of reproductive disorders,
   * testicular volume \>15 ml.
2. Healthy women:

   * between 21 and 40 years old,
   * not breastfeeding or pregnant,
   * menstrual cycles between 25 and 35 days in duration, at least 11 periods/year, with no more than 5 days variability in cycle duration,
   * no evidence for androgen excess (hirsutism or acne),
   * at screening, negative hCG pregnancy test,
   * negative screening for Factor V Leiden for those who might receive estradiol treatment as a part of this study.
3. Healthy postmenopausal women:

   * between 50 and 60 years old,
   * no menstrual periods within the last year,
   * previous history of menstrual cycles between 25 and 35 days in duration, with no more than 5 days variability in cycle duration,
   * if applicable, able to undergo washout from hormone therapy,
   * no evidence for androgen excess (hirsutism or acne),
   * negative screening for Factor V Leiden for those who might receive estradiol treatment as a part of this study.

B. Subjects with Reproductive Disorders

All subjects with reproductive disorders will meet the following criteria:

* 18 years or older,
* all medical conditions stable and well controlled,
* no prescription medications known to affect reproductive endocrine function for at least 2 months except for medications used to treat the subject's reproductive condition,
* no history of a medication reaction requiring emergency medical care,
* no illicit drug use or excessive alcohol consumption (\<10 drinks/week),
* for women, not breastfeeding or pregnant,
* if applicable, able to undergo appropriate washout from hormone therapy,
* normal physical exam and laboratory studies within protocol reference ranges,
* for women, at time of screening negative hCG pregnancy test.

Additional criteria based on subject population:

1. Men and women with hypogonadotropic hypogonadism,

   * Confirmed diagnosis by low sex steroids in the setting of low or inappropriately normal gonadotropins,
   * If needed, additional labs and imaging tests may be performed.
2. Women with Polycystic Ovarian Syndrome (PCOS)

   * Confirmed diagnosis of PCOS,
   * If needed, additional labs and imaging tests may be performed.
3. Men and women with hyperprolactinemia

   * confirmed diagnosis of elevated levels of prolactin measured via blood test,
   * no pituitary adenoma OR a microprolactinoma (\<10 mm). Patients with a macroprolactinoma confirmed on MRI imaging will be excluded,
   * willing to complete a dopamine agonist washout.