Snapshot A 52-year-old woman presents to her primary care physician with heat sensation in the upperchest and face. This is of sudden onset that later generalizes throughout the body. These episodes typically last approximately 5 minutes and is accompanied by palpitations and sweating. This occurs commonly at night and has led her to have poor sleep. She also reports feelings of vaginal dryness during daily activities. Her last menstrual period was one year ago. (Menopause) Introduction Mechanism of action estrogen acts on estrogen receptors, a member of the nuclear hormone receptors, leading to a number of effects, which includes development of female secondary sex characteristics (e.g., breasts) follicular growth endometrial proliferation increases myometrial excitability positive and negative feedback on follicle-stimulating hormone (FSH) and luteinizing hormone (LH) increases protein synthesis in the liver (e.g., steroid hormone-binding globulin) decreases bone resorption increases high density lipoprotein (HDL) and decreases low density lipoprotein (LDL) Clinical use hormone replacement therapy (HRT) to treat menopausal symptoms (e.g., hot flashes) primary ovarian insufficiency estrogen-progestin contraception to prevent unwanted pregnancies treat anovulation and hyperandrogenism in polycystic ovarian syndrome (PCOS) Toxicity increases the risk for endometrial cancer increases the risk of thrombi formation can result in postmenopausal bleeding in females exposed to diethylstilbestrol (DES), they are at risk for clear cell adenocarcinoma of the vagina can cause in increase in TBG and total hormone levels free T4 and T3 remain normal in a healthy patient, will remain euthyroid/asymptomatic