OBJECTIVE: Black cohosh (Actaea racemosa) is an herb commonly used to treat menopausal symptoms. Little is known about its effect on other physiologic parameters that could result in untoward events. This study examines the effect of black cohosh on lipids, fibrinogen, glucose and insulin. METHODS: Three hundred and fifty-one, 45-55 years old, peri or post-menopausal women experiencing vasomotor symptoms participated in a 3-month, double blind trial with randomization to: (1) black cohosh (160 mg daily); (2) multibotanical including black cohosh (200 mg daily); (3) multibotanical plus soy diet counseling; (4) conjugated equine estrogen .625 mg, with or without medroxyprogesterone acetate 2.5mg daily, for women with or without a uterus, respectively; (5) placebo. Baseline and month 3 total cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol (calculated), triglyceride, insulin, glucose, and fibrinogen serum concentrations were measured in 310 women. Baseline information was also collected on medical history, demographic characteristics, and diet. RESULTS: There were no statistically significant differences in the adjusted mean change from baseline to 3 months between the herbal groups and placebo in total cholesterol, LDL, HDL, triglycerides, glucose, and insulin. Adjusted fibrinogen levels appear to increase in the multibotanical treatment group in comparison with the other herbal groups and placebo overall (P = .02), but there was no statistically significant difference in the pairwise test against placebo (P = .11). CONCLUSIONS: Black cohosh containing therapies had no demonstrable effects on lipids, glucose, insulin or fibrinogen.