For many years, doctors routinely prescribed hormone replacement therapy (HRT) for the treatment of menopause and menopausal symptoms, as well as to reduce the risk of osteoporosis and heart disease.
Then in 2002, the results of a large, government-funded study called the Women's Health Initiative raised serious questions about HRT's benefits and risks, causing up to two-thirds of women who were on it to stop using it.
So what is HRT, is it an appropriate menopause treatment, and if so, when, and for whom?
Read on to find out answers to common questions about this popular — but controversial — menopausal symptom treatment and whether it might be right for you.
What is hormone replacement therapy?
HRT is a treatment used to augment the body's natural hormone levels, either in the form of estrogen-alone therapy (ET), for women who have had a hysterectomy (or surgical menopause) or as estrogen with progesterone therapy (EPT), for women who experience menopause naturally at midlife.
Why replace hormones?
In addition to thickening the lining of the uterus to prepare it for egg implantation, estrogen — in tandem with progesterone — serves many functions.
It helps the body to process calcium (important for the strengthening of bone), aids in maintaining healthy cholesterol levels, and keeps the vagina healthy.
With the onset of menopause, however, the amount of natural estrogen and progesterone the ovaries produce drops sharply. That, in turn, can lead to such symptoms as hot flashes, night sweats, vaginal dryness, painful intercourse, mood changes, and sleep problems.
It also can boost the risk of osteoporosis. By replenishing the body's estrogen supply, HRT can help relieve menopause symptoms and guard against osteoporosis.
When is estrogen therapy alone appropriate?
Estrogen alone is generally prescribed for women undergoing surgical menopause (the result of a hysterectomy).
When is estrogen/progesterone therapy appropriate?
The combination of estrogen and progesterone is for women who still have a uterus (that is, those who have not had a hysterectomy). For women undergoing menopause naturally, taking estrogen alone can increase the risk of developing cancer of the endometrium (the lining of the uterus).
That's because during the reproductive years, endometrial cells are discharged during menstruation, but when menstruation ceases and the endometrium is no longer shed, the addition of estrogen can cause an overgrowth of uterine cells, which, in turn, can lead to cancer.
Adding progesterone (in the form of progestin, a synthetic version of the hormone) lessens the risk of endometrial cancer by causing the endometrium to shed each month.
Who should consider HRT?
Women with moderate to severe menopausal symptoms, as well as those with a family history of osteoporosis, are candidates for hormone replacement therapy.
Who should not consider HRT?
Women with breast cancer, heart disease, liver disease, or a history of blood clots, as well as women without menopausal symptoms, are not candidates for hormone replacement therapy.
When should a woman begin HRT treatment, and how long will treatment last?
Although the average age of menopause onset is 51 and, in many women, the most severe symptoms often last for two to three years, there are no hard and fast rules about when a woman reaches menopause or about the duration of her symptoms.
Doctors say that taking a low-dose treatment — the most effective way to get HRT's benefits while limiting the possible increased risks of heart disease and breast cancer identified by the Women's Health Initiative (WHI) — for up to five years is reasonable.
"We would say if you have moderate to severe symptoms that are sufficient to interfere with your life, then by all means take hormone replacement therapy — but not for more than four or five years" at most, says Jacques Rossouw, MD, director of the WHI. "And in most cases, it's not even necessary to take it that long."
How is HRT given?
Both ET and EPT are available as a pill, a gel, a patch, and as a vaginal cream or ring (the latter two are most often recommended only for isolated vaginal symptoms).
Some doctors say there is reason to believe that a low-dose transdermal patch is the best delivery method because it sends the hormones directly into the bloodstream, bypassing the liver and therefore reducing potential metabolic risk factors.
The bottom line on HRT
Hormone replacement therapy is not the cure-all it was once thought to be, but for more severe cases, it remains the best bet for treating menopause's unpleasant symptoms and improving quality of life.
"That's something I don't think anybody would dispute," says Dr. Rogerio Lobo, MD, an OB/GYN on staff at New York City's New York Presbyterian Hospital. "Just remember to go with the lowest possible effective dose, for the shortest possible period of time."