Hot Flashes

What are hot flashes?

The most common menopause-related discomfort is the hot flash (sometimes called a hot flush). Although their exact cause is still a matter of speculation, hot flashes are thought to be the result of changes in the hypothalamus, the part of the brain that regulates the body’s temperature. If the hypothalamus mistakenly senses that a woman is too warm, it starts a chain of events to cool her down. Blood vessels near the surface of the skin begin to dilate (enlarge), increasing blood flow to the surface in an attempt to dissipate body heat. This produces a red, flushed look to the face and neck in light-skinned women. It may also make a woman perspire to cool the body down. An increased pulse rate and a sensation of rapid heart beating may also occur. Hot flashes are often followed by a cold chill. A few women experience only the chill.

Do Mother Nature's Treatments Help Hot Flashes?

Below are examples of herbal remedies that have received recognition for their potential capacity to aid in regulation and reduction of the effects of hot flashes.

Black Cohosh (Actaea racemosa, Cimicifuga racemosa): This herb has received quite a bit of scientific attention for its possible effects on hot flashes. Studies of its effectiveness in reducing hot flashes have produced mixed results. However, some women report that it has helped them. Recent research suggests that black cohosh does not act like estrogen, as once thought. This reduces concerns about its effect on hormone-sensitive tissue (eg, uterus, breast). Black cohosh has had a good safety record over a number of years. There have been some reports linking black cohosh to liver problems, but this has not been proven.

Red Clover (Trifolium pratense): In five controlled studies, no consistent or conclusive evidence was found that red clover leaf extract reduces hot flashes. As with black cohosh, however, some women claim that red clover has helped them. Studies report few side effects and no serious health problems with use. But studies in animals have raised concerns that red clover might have harmful effects on hormone-sensitive tissue.

Dong Quai (Angelica sinensis): Dong quai has been used in Traditional Chinese Medicine to treat gynecologic conditions for more than 1,200 years. Yet only one randomized clinical study of dong quai has been conducted to determine its effects on hot flashes, and this botanical therapy was not found to be useful in reducing them. Some experts on Chinese medicine point out that the preparation studied was not the same as they use in practice. Dong quai should never be used by women with fibroids or blood-clotting problems such as hemophilia, or by women taking drugs that affect clotting such as warfarin (Coumadin) as bleeding complications can result.

Ginseng (Panax ginseng or Panax quinquefolius): Research has shown that ginseng may help with some menopausal symptoms, such as mood symptoms and sleep disturbances, and with one's overall sense of well-being. However, it has not been found to be helpful for hot flashes.

Kava (Piper methysticum): Kava may decrease anxiety, but there is no evidence that it decreases hot flashes. It is important to note that kava has been associated with liver disease. The FDA has issued a warning to patients and providers about kava because of its potential to damage the liver. Because of this concern, Health Canada does not allow kava to be sold in Canada.

Evening Primrose Oil (Oenothera biennis): This botanical is also promoted to relieve hot flashes. However, the only randomized, placebo-controlled study (in only 56 women) found no benefit over placebo (mock medication). Reported side effects include inflammation, problems with blood clotting and the immune system, nausea, and diarrhea. It has been shown to induce seizures in patients diagnosed with schizophrenia who are taking antipsychotic medication. Evening primrose oil should not be used with anticoagulants or phenothiazines (a type of psychotherapeutic agent).

Use with Caution

Of course, as with all therapies, there are some risks involved. The public usually takes herbal therapies in the form of supplement pills, not as a preparation made directly from the herb by a trained herbalist. Keep in mind that herbal supplements are not as closely regulated as prescription drugs. The amount of herbal product, quality, safety, and purity may vary between brands or even between batches of the same brand. Herbal therapies may also interact with prescription dugs, resulting in dramatic changes in the effect of the botanical, the drug, or both. To be safe, tell your healthcare provider about all botanical therapies you are considering and always stop all herbal treatments at least 2 weeks before any planned surgery.

More information about herbal products can be found at HerbMed and the NIH National Center for Complementary and Alternative Medicine.