When a woman's body no longer makes estrogen, hormone therapy may be an option. But,
hormone therapy (HT), in which estrogen and progestin (a synthetic progesterone) are
used in combination, has been controversial over the years.
To learn more about women's health, and specifically hormone therapy, the National
Institutes of Health (NIH) did a study called the Women's Health Initiative (WHI) beginning
in 1991. The study involved more than 161,000 generally healthy postmenopausal women.
The study was designed to test the effects of postmenopausal hormone therapy, diet
modification, and calcium and vitamin D supplements on heart disease, fractures, and
breast and colorectal cancer in women.
The study had 2 arms:
Women with a uterus were given progestin in combination with estrogen, which is known
to prevent endometrial cancer. All women were randomly assigned to either the hormone
medication being studied or to placebo (inactive substance). Compared with placebo,
the estrogen plus progestin treatment resulted in:
Small increase in risk of heart attack (in women younger than 60 when started in perimenopause,
combined hormone therapy may reduce risk of heart attack)
Small increase in risk of stroke
Small increase in risk of blood clots
Small increase in risk of breast cancer
Reduced risk of colorectal cancer
No protection against mild cognitive impairment and increased risk of dementia (study
included only women 65 and older)
Compared with the placebo, treatment with estrogen alone resulted in:
No difference in risk for heart attack
Increased risk of stroke
Increased risk of blood clots
Reduced risk of breast cancer
No difference in risk for colorectal cancer
Reduced risk of fracture
The WHI recommends that women follow the FDA advice on hormone (estrogen-alone or
estrogen-plus-progestin) therapy. It says that hormone therapy should not be taken
to prevent heart disease.
These products are approved therapies for relief from moderate to severe hot flashes
and symptoms of vaginal dryness. Although hormone therapy may be effective in preventing
fractures, it should only be considered for women at high risk of osteoporosis who
cannot take other medicines. The FDA recommends that hormone therapy be used at the
lowest doses for the shortest time needed to achieve treatment goals. Postmenopausal
women who use or are considering using hormone therapy should discuss the possible
benefits and risks to them with their health care providers.
The National Heart, Lung, and Blood Institute offers the following suggestions for
women who are deciding whether or not to use hormone therapy:
Because the study involved healthy women, only a small number of them had either a
negative or positive effect from estrogen plus progestin therapy. The percentages
describe what would happen to a whole population—not to an individual woman. In the
estrogen plus progestin therapy study the increase risk of breast cancer was 8 additional
cases for every 10,000 women over a year. There was a 24% increase overall.
The most important thing a woman can do in deciding to continue hormone therapy is
discuss the current research with her health care provider and health care team.
Women need to be aware that taking a combined progesterone and estrogen regimen or
estrogen alone is no longer recommended to prevent heart disease. A woman should discuss
other ways of protecting the heart with her health care provider.
Women should discuss with their health care providers the value of taking combined
progesterone and estrogen therapy or estrogen to prevent osteoporosis. There may be
other treatments based on a woman's health profile.
Always consult your health care provider for more information.
What is hormone therapy?
As a woman approaches menopause, the production of estrogen and progesterone fluctuates
and then decreases significantly. Symptoms such as hot flashes often result from the
changing hormone levels. After a woman's last menstrual period, when her ovaries make
much less estrogen and progesterone, some symptoms of menopause might disappear, but
others may continue.
To help relieve these symptoms, some women use hormones. This is called menopausal
hormone therapy (MHT). This approach used to be called hormone replacement therapy
or HRT. MHT describes several different hormone combinations available in a variety
of forms and doses.
How is hormone therapy administered?
According to the American Medical Association, hormone therapy can be given in a variety
of methods, including the following:
Estrogen pills can either be taken every day or for 25 days each month. Women who
have had a hysterectomy can take estrogen alone, while those who have not may take
a combination pill (estrogen and progestin).
There are two methods—the continuous method and the cyclic method—for taking estrogen
and progestin. In the continuous method, a pill that contains both estrogen and progestin
is taken daily. Occasionally, irregular bleeding may occur.
The cyclic method involves taking estrogen and progestin separately—with estrogen
taken either every day or daily for 25 days of the month and progestin taken for 10
to 14 days of the month. This may cause monthly "withdrawal" bleeding.
estrogen and estrogen/progestin skin patches
Using this method, a patch is applied to the skin of the abdomen or buttocks for 3
or 7 days. The patch is then discarded and a new one is applied. The patch can be
left on at all times, even while swimming or bathing, and either the estrogen, or
estrogen/progestin combination is delivered through the skin into the bloodstream.
Progestin can be taken in a pill form with the patch. The patches may cause monthly
Estrogen cream is inserted into the vagina or used locally around the vulva to help
with vaginal dryness and urinary problems.
A class of drugs called selective estrogen receptor modulators (SERMs).
For women who are appropriate candidates, this type of therapy can often be customized
to provide the most benefits with the least side effects. It is important for women
to talk with their health care providers about any discomfort or menstrual symptoms
experienced with hormone treatment, as treatment approaches and dosages can be adjusted.