Estrogen, Estrogen+Progestin Therapy

Menopause is the time in a woman’s life when her period stops. It is a normal part of aging. In most women, the menopause naturally occurs between 45 and 55 years of age, but surgical removal of the ovaries or other medical conditions may cause it to occur earlier. In the years before and during menopause, the levels of female hormones can go up and down. In women, the hormone estrogen plays a key role in the reproductive system as well as maintaining healthy bones, heart, and blood vessels. Estrogen and progesterone are made mainly by the ovaries, and the production of these hormones gradually decreases as women age. With the onset of menopause, the ovaries stop making enough estrogen. This can cause symptoms such as hot flashes and vaginal dryness. At menopause, the protective effects of estrogen are lost, increasing the risk of heart disease (heart attack) and thinning of the bones (osteoporosis), while causing dryness of the vaginal walls and changes of the urinary tract.

Decreased production of estrogen by the ovaries can lead to symptoms such as hot flashes, night sweats, vaginal dryness, urinary tract infections, depression, and irritability. There are three main forms of estrogen produced by the body; estradiol, estrone and estriol. Estradiol is the most physiologically active form of estrogen. Many hormone replacement therapy (HRT) and birth-control prescription drugs contain estradiol.

Menopausal hormone replacement therapy (HRT) is a treatment in which estrogen, and often progestin, is taken to relieve the symptoms of low levels of female hormones. The benefits of HRT include:

1. Reduces the symptoms of “hot flashes.”
2. By keeping bones strong, can help prevent osteoporosis
3. Decrease pain and irritation caused by vaginal dryness.
4. HRT appears to reduce or prevent heart attacks by lowering cholesterol levels. HRT raises high-density lipoprotein (“good cholesterol”), while lowering low-density lipoprotein (“bad cholesterol”).
5. HRT appears to reduce the risk of colon cancer.

Menopausal hormone therapy with estrogen (alone or in combination with a progestin in women with a uterus) could benefit postmenopausal women by reducing cardiovascular disease, colon cancer, and other diseases of aging. Estrogen is perhaps the most well studied of all hormones. Yet results from the Women’s Health Initiative (WHI), the first major placebo-controlled, randomized clinical trial of estrogen therapy with or without progestin to prevent some chronic diseases of aging, surprised the medical community. There were more cases of stroke, blood clots, heart disease, and breast cancer in postmenopausal women using estrogen and progestin in the study, and more cases of possible dementia in women over age 65, than in those using the placebo. But, there were also fewer bone fractures and cases of colon cancer. In postmenopausal women using estrogen alone, there were more cases of stroke and fewer bone fractures than in those women on placebo. Other studies indicate that menopausal hormone therapy is effective in controlling moderate-to-severe menopausal symptoms, so research is ongoing to evaluate benefits and risks in menopausal and younger postmenopausal women. Further studies have indicated that, although estrogen remains an effective way to control hot flashes, long-term use of these hormones may increase risk for several major age-related diseases in some women, especially when treatment is started years after menopause. The results of the WHI are prompting further studies about the usefulness and safety of this therapy when used by younger menopausal and postmenopausal women to control symptoms, such as hot flashes, and to prevent chronic diseases.

With a physician’s prescription, licensed pharmacists may make a combination of natural estrogens. Whether or not natural estrogens are safe has not been well-researched. Although HRT can prevent associated problems with loss of estrogen in perimenopausal and menopausal women, it is no longer being prescribed without caution because of studies that show there is an increased risk of breast cancer, heart attacks, strokes, gall bladder disease, and blood clots.