In the 1940's when estrogen was first offered to menopausal women, it was given alone and in high doses. This growth may continue uncontrollably, resulting in cancer. Today, doctors typically prescribe a lower dose of estrogen. However, few doctors still prescribe estrogen alone to women who have a uterus. Most now prefer to add a synthetic form of progesterone called progestin to counteract estrogen's dangerous effect on the uterus.
Progestin reduces the risk of cancer by causing monthly shedding of the endometrium.
The obvious drawback to this approach is that menopausal women resume monthly bleeding. Once menopause arrives, most women enjoy the freedom of life without a period. Many are reluctant to begin their cycles again. These include breast tenderness, bloating, abdominal cramping, anxiety, irritability, and depression. Only about 15 percent of women who are eligible for hormone replacement therapy are now receiving it.