Estradiol (E2) - Serum
This test measures the amount of estradiol (e2), the form of estrogen made mainly by the ovaries. E2 plays a key role in the development of the female reproduction system, including the uterus, fallopian tubes, vagina, and breasts. Women have higher amounts of e2 during their reproductive years and almost none after menopause. Other estrogens include estrone and estriol. Estrone is the main estrogen made during menopause. In men, e2 is secreted in moderate amounts by the testes throughout life.