Effects of Ovarian Hormone Suppression on Vascular and Cognitive Function

Inclusion Criteria: * Stages of Reproductive Aging Workshop (STRAW+10) peak or late reproductive stage (-4, -3b or -3a) * Healthy based on medical history, physical examination and standard blood chemistries * Normotensive (resting blood pressure \<140/90 mmHg) * Normoglycemia (fasting glucose \<110mg/dl and hemoglobin A1c\<6.5%) * Non-smoker (for at least 12 months) Exclusion Criteria: * Serum Follical Stimulating Hormone (FSH) \>25mIU/mL measured during the first 5 days of the menstrual cycle * Use of hormonal therapy within the past 3 months * Use of antihypertensive or lipid-lowering medications * Pregnant or lactating, or planning to become pregnant during the study period * Known hypersensitivity to any of the study medications * Abnormal vaginal bleeding * History of venous thromboembolism or hormone-sensitive cancer * History of neurologic disease or major psychiatric illness * History of diagnosed learning disability or less than high-school education * Contraindication to Magnetic Resonance Imaging (MRI) scanning * Depression (Center for Epidemiological Studies - Depression (CESD) score \>16) * Significant cognitive impairment (Mini Mental State Examination (MMSE) score \<27) * Severe osteopenia or osteoporosis (proximal femur or lumbar spine T-score \< -2.0) * Body Mass Index (BMI) \>40kg/m2