Hormone Therapy

Hormone therapy is used to treat symptoms of menopause in women. Hormone therapy may include forms of estrogen and progesterone, either of which is available in a standard or bioidentical form. The chemicals used in hormone therapy not only include some increased health risks for women, but they can also survive wastewater treatment and affect the health and reproduction of aquatic species. Because of the risk to themselves and to the environment, some women may choose to manage their menopausal symptoms without hormone therapy.

Menopause is the ceasing of fertility and the menstrual cycle within a woman. It occurs naturally for each woman somewhere in her mid-40s to mid-50s. Estrogen and progesterone are produced by the ovaries and regulate the menstrual cycle. During the years before menopause, known as perimenopause, the ovaries begin shrinking, hormone levels fluctuate, and menstrual cycles often become irregular. Once a woman has gone one full year without a period, menopause has likely occurred. Menopause may also be induced surgically through the removal of both ovaries. Common symptoms of menopause include hot flashes, night sweats, insomnia, vaginal dryness, and mood swings. Hormone replacement therapy (HRT) attempts to treat these symptoms by replacing the decreased hormones within the body.

Estrogen is often taken by women using hormone therapy, most commonly in the form of 17-β-estradiol. Progesterone, or the synthetic progestin, is often combined with estrogen to thin the uterine lining. Estrogen taken alone can cause the uterine lining to grow excessively, [Page 214]which can cause uterine cancer. Women who have undergone uterine removal may safely receive estrogen alone. Those with a uterus often take progestin alone or combined with estrogen.

Some early studies on the use of hormone therapy seemed to suggest increased protection against osteoporosis, but mixed results were occurring with regard to the effects of hormone therapy overall. In an attempt to determine the effects of hormone therapy on women's health, a study of more than 161,000 healthy postmenopausal women, called the Women's Health Initiative (WHI), began in 1991. The WHI was the largest study of its kind within the United States and included clinical trials and an observational study. The results of hormone trials for estrogen alone and with progestin were as follows:

• Estrogen plus progestin: benefits—37 percent decreased risk for colorectal cancer, 37 percent less hip fractures; risks—26 percent increase in breast cancer, 41 percent increase in stroke, 29 percent increase in heart attack, doubled rates of blood clot
• Estrogen alone: benefits—39 percent less hip fractures; risks—39 percent increase in stroke, 47 percent higher risk for blood clots

The combined hormone trial was stopped early due to the increased risks of cancer and stroke. The estrogen trial was similarly stopped due to increased risks for stroke and blood clot.

Bioidentical hormones have received much public attention as an alternative to traditional hormone therapy. The chemical formula of bioidentical hormones is exactly the same as those produced by the human body. The unique feature of bioidentical hormones is that they are often presented in custom mixes of hormones, tailored for each user after the testing of saliva. These tailored mixes are often advertised as safer than traditional hormone therapies. But the Food and Drug Administration (FDA) has not tested these mixes for purity, safety, potency, or effectiveness; and they have not been approved by the FDA. For this reason, the North American Menopause Society (NAMS) does not recommend using custom-mixed hormones. FDA-approved bioidentical versions of the traditional hormonal therapies used, estrogen (estradiol) and progestin (progesterone), are available in varying doses.

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