Estrogen is a group of hormones that play an important role in the normal sexual and reproductive development in women. Estrogen is produced mainly by the ovaries, but the adrenal glands and fat cells also make small amounts of the hormones. Here are some of the effects of estrogen on womens bodies:

• Reproductive tract: Estrogen regulates the menstrual cycle and affects the reproductive tract. It helps bring about the physical changes that turn a girl into a woman, including the development of the vagina, uterus, and breasts.

• Urinary tract: Estrogen affects the urinary tract, helping to keep the bladder and urethra healthy.

• Heart and blood vessels: Estrogen affects the cardiovascular system, helping to keep blood vessels healthy and flexible. However, taking a combined progesterone and estrogen regimen or estrogen alone is no longer recommended to prevent heart disease.

• Bones: Estrogen helps protect bones against loss of mass. Although hormone therapy may help prevent osteoporosis, it should only be considered for women at high risk of osteoporosis who cannot take non-estrogen medicines.

• Breasts: Estrogen plays a role in the formation of breast tissue and helps stop the flow of milk after weaning.

• Skin, hair, and mucous membranes: Estrogen affects the skin, hair, and mucous membranes.

• Pelvic muscles: Estrogen affects the pelvic muscles, helping to keep them strong.

• Brain: Estrogen affects the brain, influencing mood, cognition, and memory.

• Secondary sexual characteristics: Estrogen is responsible for the development of pubic and armpit hair, and other secondary sexual characteristics.

Estrogen levels vary throughout a womans life, and can fluctuate during the menstrual cycle and over a female’s lifetime. Low levels of estrogen can cause symptoms such as irregular and missed periods, poor erections, infertility, loss of sex drive, and dry skin. High levels of estrogen can cause acne, loss of sex drive, osteoporosis, and depression, and very high levels can increase the risk of uterine and breast cancer.