Estrogen therapy (ET) is a treatment for women that
helps replenish low estrogen levels. This therapy involves taking the hormone
estrogen on a regular basis.
The body naturally produces less estrogen after menopause, when the
ovaries are removed, or as a result of some other health conditions. ET can
help reverse the effects of low estrogen, which may include severe menopausal
symptoms, such as hot flashes and insomnia, and long-term problems, such as
weak and brittle bones (osteoporosis).
Estrogen therapy is also called unopposed estrogen therapy because a second
hormone (progestin) is not used along with the estrogen. Estrogen used alone
can cause cancer of the lining of the uterus (endometrial cancer). For this
reason, unless a woman has had her uterus removed, estrogen usually is combined
with progestin; this combined therapy is called hormone therapy (HT).