National Institutes of Health • National Center for Complementary and Alternative Medicine
Menopausal Symptoms and CAM:
What the Science Says
The NIH State-of-the-Science conference panel discussed the evidence on several CAM therapies:
- Six botanicals—black cohosh, dong quai root, ginseng, kava, red clover, and soy
- DHEA (dehydroepiandrosterone), a dietary supplement
Very little well-designed research has been done on CAM therapies for menopausal symptoms. A small number of studies have been published, but they have had limitations (such as the way the research was done or treatment periods that may not have been long enough). As a result, the findings from these studies are not strong enough for scientists to draw any conclusions. Also, many studies of botanicals have not used a standardized product (i.e., one that is chemically consistent). The National Center for Complementary and Alternative Medicine (NCCAM) is sponsoring a number of studies on botanicals using products that are both well characterized (i.e., their ingredients have been carefully studied) and well standardized and on other CAM therapies that have shown possible promise for reducing menopausal symptoms.
Because CAM products used for menopausal symptoms can have side effects and can interact with other botanicals or supplements or with drugs, research in this area is addressing safety as well as efficacy. Some findings from this research are highlighted below.
Black cohosh (Actaea racemosa, Cimicifuga racemosa). This herb has received more scientific attention for its possible effects on menopausal symptoms than have other botanicals. Studies of its effectiveness in reducing hot flashes have had mixed results. A study funded by NCCAM and the National Institute on Aging found that black cohosh, whether used alone or with other botanicals, failed to relieve hot flashes and night sweats in postmenopausal women or those approaching menopause. Other research suggests that black cohosh does not act like estrogen, as once was thought.
United States Pharmacopeia experts suggest women should discontinue use of black cohosh and consult a health care practitioner if they have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice. There have been several case reports of hepatitis (inflammation of the liver), as well as liver failure, in women who were taking black cohosh. It is not known if black cohosh was responsible for these problems. Although these cases are very rare and the evidence is not definitive, scientists are concerned about the possible effects of black cohosh on the liver.
Dong quai (Angelica sinensis). Only one randomized clinical study of dong quai has been done. The researchers did not find it to be useful in reducing hot flashes. Dong quai is known to interact with, and increase the activity in the body of, the blood-thinning medicine warfarin. This can lead to bleeding complications in women who take this medicine.
Ginseng (Panax ginseng or Panax quinquefolius). The panel concluded 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 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.
Red clover (Trifolium pratense). The panel reported that five controlled studies found no consistent or conclusive evidence that red clover leaf extract reduces hot flashes. Clinical studies in women report few side effects, and no serious health problems have been discussed in the literature. However, there are some cautions. Some studies have raised concerns that red clover, which contains phytoestrogens, might have harmful effects on hormone-sensitive tissue (for example, in the breast and uterus). (See box below for more information on phytoestrogens.)
Soy. The scientific literature includes both positive and negative results on soy extracts for hot flashes. When taken for short periods of time, soy extracts appear to have few if any serious side effects. However, long-term use of soy extracts has been associated with thickening of the lining of the uterus.
Some botanical products, such as soy and red clover, contain estrogen-like compounds called phytoestrogens. Plants rich in phytoestrogens may help relieve some symptoms of menopause. However, it is uncertain whether this relief comes from phytoestrogens or from other compounds in the plant. Much remains to be learned about these plant products, including exactly how they work in the human body. Doctors caution that certain women need to be particularly careful about using phytoestrogens, especially:
- Women who have had or are at increased risk for diseases or conditions that are affected by hormones, such as breast, uterine, or ovarian cancer; endometriosis; or uterine fibroids
- Women who are taking drugs that increase estrogen levels in the body, such as birth control pills; MHT; or a type of cancer drug called selective estrogen receptor modulators (SERMs), such as tamoxifen.
DHEA is a naturally occurring substance that is changed in the body to the hormones estrogen and testosterone. It is also manufactured and sold as a dietary supplement. A few small studies have suggested that DHEA might possibly have some benefit for hot flashes and decreased sexual arousal, although small randomized controlled trials have shown no benefit. Because levels of natural DHEA in the body decline with age, some people believe that taking a DHEA supplement can help treat or prevent conditions related to aging; however, there is no good scientific evidence to support this notion.
Concerns have been raised about whether DHEA is safe and effective. Its long-term effects, risks, and benefits have not been well studied, and scientists are not certain whether it might increase the risk for breast or prostate cancer. Before using DHEA for any purpose, people should talk to their health care provider about potential benefits and risks.
NCCAM Clinical Digest is a service of the National Center for Complementary and Alternative Medicine, NIH, DHHS. NCCAM Clinical Digest, a monthly e-newsletter, offers evidence-based information on CAM, including scientific literature searches, summaries of NCCAM-funded research, fact sheets for patients, and more.
The National Center for Complementary and Alternative Medicine is dedicated to exploring complementary and alternative healing practices in the context of rigorous science, training CAM researchers, and disseminating authoritative information to the public and professionals. For additional information, call NCCAM’s Clearinghouse toll-free at 1-888-644-6226, or visit the NCCAM Web site at nccam.nih.gov. NCCAM is 1 of 27 institutes and centers at the National Institutes of Health, the Federal focal point for medical research in the United States.
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