According to the findings of a small one year phase II study, black cohosh and red clover did not reduce the number of menopausal vasomotor symptoms compared with placebo.

This study involved 89 women experiencing at least 35 vasomotor symptoms per week (hot flushes and night sweats) in the 2 weeks before study enrollment. They were randomised to receive black cohosh (128 mg/d standardised to 7.27 mg triterpene glycosides), red clover (398 mg/d standardised to 120 mg isoflavones), placebo, and 0.625 mg conjugated equine oestrogens plus 2.5 mg medroxyprogesterone acetate (CEE/MPA; control group).

The primary endpoint was the reduction vasomotor symptoms, hot flushes alone, and intensity of hot flushes as compared with placebo. Secondary outcomes included safety evaluation, reduction of somatic symptoms, relief of sexual dysfunction, and overall improvement in quality of life. The following findings were reported after 12-months of treatment:

• Black cohosh and red clover did not significantly reduce the frequency of vasomotor symptoms as compared with placebo: the reduction in number of vasomotor symptoms was 34% for black cohosh, 57% for red clover, 63% for placebo and 94% for CEE/MPA.

• There were no significant differences for most of the secondary outcomes between any of the treatment groups and placebo at any of the time points measured.

• There were no significant differences between the herbal treatments and placebo for any of the safety parameters including breast and endometrial safety, liver enzymes, blood