There is little or no evidence that herbal remedies used to treat symptoms of menopause work, suggests a new report, which also found that some of these products are linked to serious side effects.
Herbal remedies such as black cohosh, red clover, dong quai, evening primrose oil and ginseng are commonly used as alternative treatments for menopause symptoms that include hot flushes and night sweats, which are caused by falling estrogen levels.
Between 30 per cent and 70 per cent of women experience these symptoms, which can last anywhere from four to 12 years.
However, a review of 26 studies on the efficacy of these treatments showed there is little evidence that they work and not enough research into the potential side effects or contraindications if mixed with conventional medications.
The review, conducted by Dr. Ike Iheanacho, also included studies on wild yam extract, chaste tree, hops, sage leaf and kava kava. It is published in the January issue of Drug and Therapeutics Bulletin.
According to the review, more women have turned to herbal remedies to relieve menopause symptoms over the last seven years. In 2002, some studies suggested that hormone replacement therapy, which replenishes hormone levels and can ease menopause symptoms, may increase the risk of breast and ovarian cancers and heart problems.
The review found "no convincing evidence" that red clover extract is effective, and little evidence for dong quai, evening primrose oil, wild yam, chaste tree, hops, or sage.
The findings also showed that black cohosh can cause liver toxicity, and that dong quai and ginseng can interfere with the anti-clotting drug warfarin.
"Such products are often assumed to be 'safe' on the grounds that they are 'natural,' and many patients do not tell their doctors that they are taking herbs," Iheanacho wrote. "In reality, however, herbal medicines have pharmacological actions, and so can cause unwanted effects and have potentially dangerous interactions with other medicines (both herbal and conventional)."
The review also found that studies investigating herbal remedies are often poorly designed, include too few participants or don't last long enough for the findings to be clinically significant.
As well, the chemical make-up of the same herb will vary between manufacturers, making the results of different studies hard to compare.
Iheanacho recommends that doctors frequently ask their patients if they are taking herbal remedies in order to discuss the potential risks and benefits.
