Black cohosh, either alone or as part of a multibotanical, does not provide significant relief from vasomotor symptoms associated with perimenopause, according to the results of a 1-year, randomized, double-blind, placebo-controlled trial. 

The study compared daily use of: (1) black cohosh, 160 mg alone; (2) a multibotanical containing 200 mg black cohosh and nine other ingredients; (3) a multi botanical plus dietary soy counseling; (4) conjugated equine estrogen, 0.625 mg with or without medroxy progesterone acetate, 2.5 mg; and (5) placebo. 

The researchers found that the number and intensity of vasomotor symptoms did not differ significantly between the herbal interventions and placebo at 1 year or at any quarterly checkpoint leading up to 1 year. In fact, at 1 year, symptom intensity was significantly worse with the multibotanical plus soy counseling than with placebo. The only thing that truly helped was the hormone therapy, which, compared with placebo, resulted in –4.06 vasomotor symptoms per day for the average over all the follow-up time points (95% CI, –5.93 to –2.19 symptoms per day; 