Hormone therapy comes in two forms: a combination of estrogen and a synthetic form of the hormone progesterone (progestin) - a combination known as HT -- and estrogen-alone therapy, or ET, when estrogen alone is prescribed. HT is typically given to women who have not had hysterectomies because estrogen is known to increase the risk of uterine cancer. The addition of progestin decreases estrogen's effects on the uterine lining, thus reducing this risk. Both HT and ET are available in a variety of applications: pills, creams, skin patches, vaginal ring and injections. Recent major scientific studies have found significant health risks, including higher risk for breast cancer, in postmenopausal women using a form of estrogen plus progestin hormone replacement therapy (or combination HT).

This definition is in context to Female Health. See more contextual defintions for Hormone Therapy (Ht).