More than 50% of women going through menopause experience hot flashes, the most common symptom of menopausal transition. Estrogen has been used for decades as a hormone supplement to reduce symptoms of menopause.

Recent studies showing harmful effects of estrogen, including increased risk of cardiovascular events and breast cancer, have intensified the search for other ways to treat menopausal symptoms. Some nonhormonal alternatives to estrogen include antidepressants and other medications, herbs, soy, and dietary supplements, as well as stress management, acupuncture, chiropractic, and massage. There's very little support for the effectiveness of these therapies, and estrogen is currently the only therapy approved by the US Food and Drug Administration (FDA) for this purpose.

Researchers interested in comparing the effectiveness and safety of nonhormonal therapies on hot flashes reported their review of clinical trials in the May 3, 2006, edition of the Journal of the American Medical Association (JAMA) . Their results showed supportive evidence of effectiveness for ingested nonhormonal therapies among a small number of studies. The safety of these therapies is a concern, as most have side effects and have only been studied for a short period of time. Researchers concluded that estrogen replacement remains the safest and most effective treatment for hot flashes.

About the Study

Heidi D. Nelson, MD, PhD, and colleagues at the Oregon Health and Science University and Providence Health System in Portland, OR, conducted a systematic review and meta-analysis of clinical trials to compare nonhormonal therapies for hot flashes. Researchers used studies that compared women who were treating their symptoms with nonhormonal therapies to those taking a placebo. They found 43 studies that met their inclusion criteria, including ten trials of antidepressants, ten trials of clonidine (an older antihypertensive medication), six trials of other prescribed medications including gabapentin (an antiseizure medication), and 17 trials of isoflavone extracts derived from red clover and soy. The frequency of hot flashes was measured at the beginning and end of each study. Comparisons between these measures were used to determine how effective the therapies were in reducing the frequency of hot flashes.

In the review, some of the antidepressants, clonidine, and gabapentin trials showed modest evidence for reducing hot flashes, while others showed no reduction in frequency. The isoflavones trials either showed no reduction in frequency of hot flashes or had mixed results. In nearly all of the trials, adverse side effects were documented. These effects included dry mouth, nausea, headaches, drowsiness, insomnia, and anxiety, among others, and they ranged in severity.

There were several limitations of the review and meta-analysis. Not many trials on nonhormonal therapies have been published, and those that have suffer from methodological problems. Most of these trials have small numbers of participants, which limits the generalizability of their results; they are also short in duration and therefore do not provide information about long-term outcomes or adverse effects.

How Does This Affect You?

Every woman has a different experience with menopause. The best choice of treatment, including no treatment at all, depends on the severity of her symptoms and their impact on her quality of life. For most women, hot flashes go away in a matter of months or years, though for some, they persist for much longer and can be debilitating.

This study indicates that estrogen therapy is still the most effective treatment for hot flashes. It also supports previous findings that the lowest dose should be used for the shortest period of time needed for symptoms to improve or go away. Nonhormonal alternatives are likely not the best option for women who tolerate estrogen, but should be considered by those at risk for cardiovascular disease, breast cancer , or blood clots.

If your symptoms are mild, you may find relief through simple lifestyle changes like dressing in layers, keeping rooms cool, not smoking, avoiding foods and drinks that trigger hot flashes, managing stress, and especially exercising regularly. If your symptoms are more severe or do not respond to these measures, talk to your doctor about the benefits and risks of both estrogen therapy and nonhormonal alternatives.