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Hormone therapy (HT) is a medical treatment with a medication containing one or more female hormones, commonly estrogen plus progestin (synthetic progesterone), and sometimes testosterone. Some women, usually those who have had their uterus removed, receive estrogen-only therapy.
HT is most often used to treat symptoms of menopause, such as hot flashes, vaginal dryness, mood swings, sleep disorders, and decreased sexual desire. Hormone therapy comes as a pill, patch, injection, or vaginal cream.
- Alternative Names
HRT; Estrogen replacement therapy; ERT; Hormone replacement therapy
Hormone therapy used to be widely regarded as a very safe treatment for menopause. However, several major studies have shown that hormone therapy creates risks for certain medical conditions and problems, including heart disease, stroke, and cancer.
However, hormone therapy may help relieve some of the bothersome symptoms of menopause, such as hot flashes, vaginal dryness and pain with intercourse, and long-term complications of estrogen loss, such as osteoporosis.
You and your doctor should decide whether hormone therapy is right for you. The key is to weigh the risks associated with taking hormone therapy against your risk of heart disease or osteoporosis without taking hormone therapy. Every woman is different. Your doctor should be aware of your entire medical history when considering prescribing hormone therapy.
At this time, short-term use (up to 5 years) of hormone therapy at the lowest possible dose to treat the symptoms of menopause still appears to be safe for many women.
BENEFITS OF HORMONE THERAPY
Perhaps the largest benefit women receive from hormone therapy is relief from:
- Hot flashes
- Night sweats
- Sleep difficulties
- Vaginal dryness
Usually, hot flashes and night sweats are less severe after a couple of years, especially if hormone therapy is slowly reduced.
A woman's body produces less estrogen during and after menopause, which may affect her bone strength. Hormone therapy may also prevent the development of osteoporosis. For information on treating bone loss, see: Osteoporosis.
Studies have not been able to definitely show that hormone therapy helps with urinary incontinence, Alzheimer's disease or dementia, or colon cancer.
RISKS OF HORMONE THERAPY
Doctors have long known that taking estrogen increases a person's risk for blood clots. Generally, this risk is higher if you use birth control pills, which contain high doses of estrogen. Your risk is even higher if you smoke and take estrogen. The risk is not as high when estrogen skin patches (transdermal estrogen) are used.
Breast cancer: Woman who take estrogen therapy for a long period of time have a small increase in risk for breast cancer. Most guidelines currently consider hormone therapy safe for breast cancer risk when taken for up to 5 years.
Endometrial/uterine cancer: The risk for endometrial cancer is more than five times higher in women who take estrogen therapy alone, compared with those who do not. However, taking progesterone with estrogen seems to protect against this cancer. Endometrial cancer does not develop in women who do not have a uterus.
Heart disease: Estrogen may increase the risk of heart disease in older women. However, it may still be somewhat protective in preventing heart disease when given under certain circumstances. Estrogen is probably the safest for women under 60 years of age.
Stroke: Women who take estrogen have an increased risk for stroke.
Several studies have shown that women who take estrogen/progestin therapy have an increased risk for developing gallstones.
SIDE EFFECTS OF HORMONE THERAPY
As with all medicines, side effects are possible. Some women taking hormone therapy may have water retention, bloating, nausea, breast soreness, mood swings, and headaches. Changing the dose or form of hormone therapy may help reduce these side effects.
Some women have irregular bleeding when they start taking hormone therapy. Changing the dose often eliminates this side effect. Close follow-up with your doctor is important when you have any unusual bleeding.
FORMS OF HORMONE THERAPY
Hormone therapy is available in various forms. It may be necessary to try more than one form before finding the one that works best for you.
Estrogen comes in the following forms:
- Nasal spray
- Pills or tablets, taken by mouth
- Skin gel
- Skin patches, which are applied to the thigh or belly area
- Vaginal creams or vaginal tablets, to help with dryness and pain with sexual intercourse
- Vaginal ring
Most women who take estrogen and who have not had their uterus removed also need to take progesterone. Taking these medicines together helps reduce the risk of endometrial (uterine) cancer.
Progesterone or progestin comes in the following forms:
- Skin patch
- Vaginal cream
When estrogen and progesterone are prescribed together, your doctor will recommended one of the following schedules:
- Cyclic hormone therapy is often recommended when a woman is starting menopause. With this therapy, estrogen is taken in pill or patch form for 25 days, with progestin added somewhere between days 10 - 14. The estrogen and progestin are used together for the remainder of the 25 days. Then, no hormones are taken for 3 - 5 days. There may be monthly bleeding with cyclic therapy.
- Continuous, combined therapy involves taking estrogen and progestin together every day. Irregular bleeding may occur when starting or switching to this therapy. Most women stop bleeding within 1 year.
Additional medications may be recommended for some women with severe symptoms from menopause, or women who are at very high risk for osteoporosis or heart disease. One of these supplemental drugs might be testosterone, a hormone that is more plentiful in males, to improve sex drive. Nonhormonal medications are sometimes used either in addition to, or instead of, hormone therapy.
In addition to hormone therapy, a woman can take other steps to adjust to the changes in life during menopause. Eating healthy foods and getting regular exercise will also help decrease bone loss and maintain healthy heart muscle.
CALLING YOUR HEALTH CARE PROVIDER
It is important to have regular checkups with your health care provider when taking hormone therapy. If you have vaginal bleeding during hormone therapy or other unusual symptoms, call your health care provider.
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Review Date: 9/2/2009
Reviewed By: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.