Estrogen is a major female sex hormone that is crucial to a woman’s development, ability to bear children and overall health. It is the hormone responsible for monthly menstruation and many changes throughout a woman’s life. Around the age of 50, the level of estrogen and other adrenal hormones such as progesterone begin to decline, and a woman stops menstruating. This time, known as menopause, is marked by a significant decrease in the amount of sex hormones produced by a woman’s body.

Estrogen appears to have a number of potent health benefits, including protection from heart disease and osteoporosis. Thus, when a woman enters menopause, her risk of heart disease begins to climb until it equals that of men. Similarly, she is at increased risk for bone diseases such as osteoporosis and cognitive diseases such as Alzheimer’s.

Hoping to recapture the benefits of estrogen for women in menopause, physicians began recommending hormone replacement therapy (HRT) with synthetic estrogen for post-menopausal women. Also, hormone replacement therapy was frequently prescribed to alleviate the symptoms of menopause, including hot flashes and other bothersome side effects, and for women who have had their ovaries removed after an illness.

Because estrogen-only therapy (e.g., unopposed estrogen) is associated with increased risk of certain cancers, progesterone was often paired with the estrogen, which reduced the risk of developing a hormone dependent cancer.

Recently, however, the clinical benefits of HRT have come under intense scrutiny. While HRT was effective for controlling the symptoms of menopause and reducing the risk of certain diseases, several major studies linked HRT to an increased risk of heart disease, blood clots, stroke and breast cancer. Current debate includes such considerations as:

Regardless of whether or not women choose to take HRT, all women are encouraged to make healthy lifestyle changes such as quitting smoking, eating a heart-healthy diet and controlling conditions such as diabetes and high blood pressure.