Estradiol is a sex steroid hormone produced in the ovaries of women and the adrenal cortex of both sexes. In men, testosterone is transformed into estradiol in peripheral tissues.

Estradiol is considered a "female" sex hormone, since one of its most important functions is to ensure the development of the body according to the female type.

During intrauterine development, estradiol helps the reproductive organs adopt a female type, after birth it forms secondary sex characteristics: breast growth, female-type hair, wide pelvis and narrow shoulders, menstrual cycle, higher body fat percentage and distribution. The special role of estradiol is to maintain reproductive function. The hormone is necessary for egg cell maturation, growth and development of the uterus during pregnancy. Menopause is caused by programmed decline in ovaries function, which leads to a decrease in estradiol, and a hormone deficiency syndrome develops.

The syndrome has a number of characteristic signs that are directly related to decrease in estradiol levels. osteoporosis develops - a decrease in bone tissue. Estradiol has an antiresorptive ability, i.e. the ability to prevent the leaching of calcium from the bones. the risk of cardiovascular disease increases and body weight increases, which is associated with the violation of the function of estradiol to regulate the amount of cholesterol. there are “flushes” - a short-term episodic feeling of heat and sweating.

A decrease in the concentration of estradiol is a direct cause of "hot flashes". mood changes (up to depression) and decreased sexual desire. Estradiol is responsible for woman's psycho-physiological behavior. atrophy of the vaginal mucosa, which leads to vaginal dryness, painful sexual intercourse. flabbiness and reduction in the size of the breast. An important condition for the normal functioning of estrogen is its proportional relationship with testosterone. The level of estradiol in the body is regulated by other hormones – FSH, LH, prolactin.