Objective: Many women have turned to complementary and alternative medicines for relief from their menopausal symptoms. The prevalence of herbal medicinal product use among menopausal women highlights the need for investigation into these interventions. The aim of this study was to evaluate the benefit of herbal medicinal products for the treatment of menopausal symptoms by performing a systematic review of randomized clinical trials.
Design: Literature searches of four computerized databases were done to identify randomized clinical trials of herbal medicinal products for the treatment of menopausal symptoms. Manufacturers of herbal products were contacted, and our own files were also searched. There were no restrictions on the language of publication. Trials were considered if the outcome measures related to the physical or psychological impact of menopause, whether by compendium scores, questionnaires, or women's symptom diaries, excluding studies describing artificially induced menopause. This review was not concerned with biochemical or pathological data.
Results: Eighteen randomized clinical trials that fit our criteria were identified. These studies investigated black cohosh (n = 4), red clover (n = 4), kava (n = 3), dong quai (n = 1), evening primrose oil (n = 1), ginseng (n = 1), and combination products (n = 4). Trial quality was generally good, with 16 of 18 studies scoring 3 or more (maximum 5) on the Jadad Scale.
Conclusions: There is no convincing evidence for any herbal medical product in the treatment of menopausal symptoms. However, the evidence for black cohosh is promising, albeit limited by the poor methodology of the trials. The studies involving red clover suggest it may be of benefit for more severe menopausal symptoms. There is some evidence for the use of kava, but safety concerns mean this herbal product is not a therapeutic option at present. The evidence is inconclusive for the other herbal medicinal products reviewed.
The most common conventional medical treatment for menopausal symptoms is hormone replacement therapy (HRT). The primary reason women use HRT is for the relief of vasomotor symptoms attributed to menopause, although there is evidence for other benefits, such as protection against bone loss and ischemic heart disease. 1 However, there is also recent evidence to suggest that HRT may increase breast cancer, heart attacks, coronary attacks, and strokes. 2
It seems that because of a fear and dislike of adverse effects as well as these possible long-term risks of HRT, many women have turned to complementary and alternative medicines, hoping that these might relieve menopausal symptoms. 3,4,5
In a study of 500 women by the Women's Nutritional Advisory Service, the most common reason cited for not taking HRT was concern over risks. 5 In a survey of 100 menopausal women carried out in the US, 29% were taking HRT, 16% used HRT plus dietary supplements, 32% used dietary supplements alone, and 13% were on no medication. 6
It has been estimated that over one third of North American adults use herbal medicinal products (HMPs) at an annual cost of $13.7 billion. 7 A Swedish study suggests that approximately 4% of women treat their menopausal symptoms this way. 8 HMPs have been promoted for both the physical and psychological symptoms of menopause. Some are thought to have estrogenic effects, eg, red clover. In general, the actual mechanisms involved are still to be elucidated. Other herbal medicines, such as kava, are used to relieve anxiety in menopause. In addition, it is well documented that there is a marked placebo and time effect on menopausal symptoms during trials. 9
The aim of this systematic review is to summarize and critically analyze all relevant randomized clinical trials (RCTs) on this topic.