Evaluation of Kisspeptin Glucose-Stimulated Insulin Secretion With Oral Glucose Tolerance Test

Inclusion Criteria: History: * over the age of 18, * normal pubertal development * stable weight for previous three months, * normal body mass index (BMI between 18.5-25) * regular menstrual cycles Physical examination: • systolic BP \< 140 mm Hg, diastolic \< 90 mm Hg Laboratory studies: (per Massachusetts General Hospital reference ranges) * normal hemoglobin * hemoglobin A1C \< 6.5% * blood urea nitrogen, creatinine not elevated * aspartate aminotransferase, alanine aminotransferase \< 3x upper limit of normal Exclusion Criteria: * active illicit drug use, * history of a medication reaction requiring emergency medical care, * difficulty with blood draws. * history of chronic disease, except well controlled thyroid disease, * recent use of prescription medications which interfere with metabolism or reproduction (recent = within 5 half-lives of the drug). Use of levothyroxine or seasonal allergy medications is acceptable, * history of diabetes in a first degree relative, * use of contraceptive pills, patches or vaginal rings within last 4 weeks. * hyperlipidemia by fasting lipid panel * positive serum pregnancy test (for all women)