Effects of black cohosh (Cimicifuga racemosa) on bone turnover, vaginal mucosa, and various blood parameters in postmenopausal women: a double-blind, placebo-controlled, and conjugated estrogens-controlled study.

OBJECTIVES: In this study, the effects of the Cimicifuga racemosa (CR) preparation CR BNO 1055 on markers of bone metabolism, hormones, sex hormone-binding globulin (SHBG), lipometabolism, vaginal maturity, and routine laboratory parameters were compared with those of conjugated estrogens (CE) and placebo.

DESIGN: Sixty-two postmenopausal women were included in this double-blind study. Treatment duration with CR (daily dose corresponds to 40 mg of herbal drug), CE (0.6 mg/day), or placebo was 12 weeks. Markers of bone turnover (bone-specific alkaline phosphatase, CrossLaps), estradiol, follicle-stimulating hormone, leuteinizing hormone, SHBG, triglycerides, total cholesterol, high-density cholesterol, low-density cholesterol, and routine clinical chemistry parameters were determined from blood samples. Vaginal "maturity index" was determined from vaginal smears.

RESULTS: The analyses of bone turnover markers indicated beneficial effects for CR and CE on bone metabolism. CR stimulated osteoblast activity, whereas CE inhibited osteoclast activity. Whereas CE showed strong estrogenic effects on vaginal mucosa, CR showed weak estrogen-like activity. No significant effects were seen on coagulation markers and liver enzymes in the blood. CR was well tolerated.

CONCLUSION: These results suggest that CR has beneficial bone remodeling and weak estrogen-like effects in the vaginal mucosa.