Menopausal hormone therapy (MHT)—also called postmenopausal hormone therapy and hormone replacement therapy—is sometimes used to replace the natural hormones estrogen and progesterone in a woman’s body during and after menopause, when levels of these hormones drop. Providers may recommend MHT to relieve common symptoms of menopause, such as hot flashes and vaginal dryness, and to address long-term biological changes, such as bone loss (osteoporosis), that result from declining levels of estrogen and progesterone.
Like most therapies, MHT has not only potential benefits but also possible harms. People should discuss the likely benefits and harms they might experience with their providers before deciding whether to use MHT and what form to use.
MHT usually consists of estrogen alone or estrogen plus progestin, a synthetic form of progesterone. The hormones used in MHT are approved by the U.S. Food and Drug Administration (FDA) and come from a variety of plants and animals or are made in a laboratory. The chemical structure of these hormones is similar to those of hormones produced by women’s bodies. MHT can be given in a variety of ways. When the goal is to treat hot flashes and other systemic symptoms or to prevent osteoporosis, it is usually given as a pill, but it can be also be given systemically through the skin (e.g., via a patch, gel, or spray) or via an implant. When the goal is to address genitourinary symptoms such as vaginal dryness, MHT (containing low-dose estrogen only) is applied directly in the vagina (as a cream or suppository).
Which form of MHT is used depends on whether a woman has a uterus. Because estrogen, when used alone (i.e., without progestin) for systemic MHT, is associated with an increased risk of endometrial cancer, estrogen is used alone only in women who have had a hysterectomy. Women who have a uterus—that is, who have not had a hysterectomy—are generally prescribed estrogen plus progestin for systemic MHT. Vaginal estrogen to treat genitourinary symptoms is prescribed regardless of hysterectomy status.
Non-FDA-approved hormone products, sometimes referred to as “bioidentical hormones,” are custom-mixed (or compounded) drugs that are sometimes sold without a prescription on the internet. Claims that these products are “safer” or more “natural” than FDA-approved hormonal products are not supported by credible scientific evidence. More information about these products can be found on FDA’s Menopause & Hormones: Common Questions fact sheet.