Why is progestogen taken?
When taken without progestogen, estrogen increases a woman’s risk of cancer of the endometrium, the tissue lining the uterus. Estrogen stimulates cell growth in the endometrium. During a woman’s reproductive years, endometrial cells are shed during menstruation. When the endometrium is no longer shed, estrogen can cause an overgrowth of cells in the uterus, a condition that can increase a woman’s risk of endometrial cancer. Progestogens reduce the risk of endometrial cancer by making the endometrium shed each month. As a result, women who take progestogen may have monthly bleeding. Monthly bleeding can be lessened and, in some cases, eliminated by taking progestin and estrogen together continuously. Women who have had hysterectomies do not usually need to take progestin.
