Estradiol and Fear Extinction in Anorexia Nervosa (AN)

Inclusion Criteria (AN): * Previous diagnosis of recent AN with BMI of \<18.5 (within past year) * Current BMI \> 19.0 and \< 23.0 kg/m2 * Amenorrhea or oligomenorrhea Inclusion Criteria (Healthy Controls): * BMI \> 19 \< 23 kg/m2 * Taking hormone-based contraceptives for a period of one month or more * Eating disorders symptom scores within one standard deviation of healthy controls Exclusion Criteria (AN): * Any medical or psychiatric problem requiring urgent medical or psychiatric attention, including acute suicidality * History of breast cancer, deep vein thrombosis, pulmonary embolism, myocardial infarction or stroke, diabetes, liver disease, known thrombophilic disease * Currently taking estrogen or progesterone medication * Tobacco use greater than 1 pack per week * Use of St. John's Wort, Phenobarbital, phenytoin, carbamazepine, rifampin, and dexamethasone can all decrease plasma estrogen level because they are CYP3A4 inducers. Cimetidine, erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice as these may increase plasma estrogen, potentially increasing the presence of side effects * Pregnant, lactating or unwilling to use appropriate birth control (which may include abstinence) to prevent pregnancy for the duration of study participation (i.e. up to 4 weeks) * Allergy to estradiol or medroxyprogesterone or ingredients in food items used for test meals * Undiagnosed, abnormal vaginal bleeding Exclusion Criteria (Healthy Controls): * Ever diagnosed with an Eating Disorder * Any medical or psychiatric problem requiring urgent medical or psychiatric attention, including acute suicidality * Pregnant, lactating or unwilling to use appropriate birth control (which may include abstinence) to prevent pregnancy for the duration of study participation (i.e. up to 4 weeks) * Food allergies to items in the test meal