Estradiol is a form of estrogen, a hormone that plays a crucial role in the development and regulation of the female reproductive system and secondary sexual characteristics. It is involved in various bodily functions, including the menstrual cycle, bone health, and cardiovascular health. Estradiol is often used in hormone replacement therapy to manage symptoms of menopause, such as hot flashes and vaginal dryness, and to prevent osteoporosis. Additionally, it can be used in certain medical conditions related to hormone imbalances.