Dong quai (Angelica sinensis)
Dong quai, a common Chinese herb extracted from the Angelica sinensis root, has become popular in the U.S. In contrast to China, where it is sold as part of a mixture that includes several other herbs, dong quai typically is sold in the U.S. as a single herb.
Although some women report improvements in their vasomotor symptoms, there have been very few studies on the effects of dong quai on menopause. In one study of 71 postmenopausal women over a 24-week period, researchers could not demonstrate a difference between dong quai and placebo in alleviating vasomotor symptoms.20 The investigators suggested that studying the effects of dong quai alone, rather than in combination with other herbs, may have been a factor in their findings.
Two caveats: Dong quai increases photosensitivity, so women taking the herb should be cautioned that too much exposure to sunlight may result in a rash. Also, it has been reported to potentiate the effects of warfarin (Table 2, 3, and 4). It should not be used during pregnancy.21
Evening primrose (Oenothera biennis)
Native Americans consumed the leaves, roots, and seedpods of this plant for food, and made extracts from it to treat a variety of conditions. Today, the flowers and seeds are pressed to make oil that is high in gammalinolenic acid (GLA) and essential polyunsaturated fatty acids, which convert into prostaglandins. Evening primrose oil also is a good source of linoleic acid and the omega-6 fatty acid γ-linoleic acid.
Because red clover contains warfarin, high dosages may cause the blood to thin.
Although there are a number of good studies in which evening primrose oil has been used to successfully treat eczema and several other conditions with few side effects, it appears to have no benefit over placebo for hot flushes.22
Patients should be warned that mild upset stomach, indigestion, nausea, softening of stools, and mild headaches may occasionally occur. Also, evening primrose is contraindicated in women taking conventional medication for temporal lobe epilepsy or schizophrenia, as the substance decreases the efficacy of those drugs (Table 2, 3, and 4).
Red clover (Trifolium pratense)
Red clover is a plant that contains the phytoestrogens formononetin, biochanin A, daidzein, and genistein. It was originally used by Native Americans to treat whooping cough, gout, and cancer.
Two clinical trials conducted in Australia failed to demonstrate that red clover extract was more effective than placebo in reducing vasomotor symptoms.23,24 However, one study found that women who took 40 mg of red clover per day—the recommended dosage—experienced a significant reduction in hot flushes.25
There is still little information on whether red clover will have any effect on the uterine lining or breast tissue. Because red clover contains warfarin, high dosages may cause the blood to thin (Table 2, 3, and 4).
Conclusion
Whether to take HRT is one of the major decisions women in perimenopause or early menopause have to make. The overwhelming majority will decide against it, either out of fear of potential risks or simply to avoid unpleasant side effects. In fact, several studies have shown that only 15% to 20% of women will take HRT for more than a year.2 Even women who do agree to take HRT frequently demonstrate poor compliance.
But patients who decline HRT do need—and will have—other choices to help them weather vasomotor symptoms that can greatly disrupt their lives. Many women find these plant-based alternatives an important option that allows them to control their hot flushes without taking HRT.
As clinicians start to recommend alternative supplements to their menopausal patients, they should do so with an understanding of the expected results, potential risks and benefits, and how the recommendation may interact with other medications. If these guidelines are followed, physicians may recommend alternative treatments with the same confidence they have in prescription drugs.
The author reports no financial relationship with any companies whose products are mentioned in this article.