Estradiol (E2) is a hormone produced in females mainly in the ovaries which helps in the growth & development of female sex organs like uterus, vagina, fallopian tubes & breast. It is also produced by adrenal glands & placenta. E2 also helps to control fat distribution in the body of women and is needed for the health of bones & joints. Males also have estrogens produced by testes & adrenal gland but the level is very low. Women need to test their E2 levels if they have abnormal periods, delayed puberty, suffer from infertility or have symptoms of menopause. Tumors in the ovaries also affect the E2 levels.