The REgistry of Very Early Estrogen and AnovuLation

Inclusion Criteria: * 3 or more months of consecutive amenorrhea with a diagnosis of functional hypothalamic amenorrhea or screening hormones consistent with functional hypothalamic amenorrhea including but not limited to: * Estradiol: \< 50pg/mL * LH: \< 10 IU/mL * FSH: \< 10 IU * Testosterone: 2 - 45 ng/dL * Free Testosterone: 0.1 - 6.4 pg/mL * FT4: 0.93 - 1.70 ng/dL * Prolactin: \< 20 ng/mL * AMH: \> 1 ng/mL * Urine or serum human chorionic gonadotropin: Negative * LH:FSH Ratio \<1 * No signs of male-like hair growth on the upper lip, chin, chest, abdomen, buttocks, or back * Does not have a diagnosis for secondary amenorrhea, including prolactinoma, PCOS, premature ovarian insufficiency, pituitary surgery, infection, or infarction * Premenopausal status determined by WISE criteria * Able to give informed consent * Able to read English Exclusion Criteria: * Parturition/lactating in the last 6-12 months * Lack of consent