This randomized, double-blind, placebo-controlled clinical trial was conducted in Iran with a total of 84 postmenopausal women. Women were randomly assigned to one black cohosh tablet per day (n=42) or one placebo (n=42) per day for 8 weeks. The severity of vasomotor symptoms and number of hot flashes were recorded in the pre-treatment phase and 4 and 8 weeks after intervention. In Iran, black cohosh is supplied by Goldaru Pharmaceutical Company under the name of Cimifugol and each tablet contains 6.5 mg of dried extract of black cohosh root, equal to 0.12 to 0.18 mg of 27 deoxy ectoine.
Participants were postmenopausal women ages 45 to 60 years old were included in the study if no menses for 12 consecutive months, normal blood pressure, a minimum score of 2 for vasomotor symptom severity; no history of breast or cervical cancer, liver disease, abnormal postmenopausal bleeding, depression or hyperthyroidism and no psychiatric medications or hormones or herbs used for treating menopausal symptoms. In addition, no smoking and no alcohol use were also inclusion criteria.
The primary outcome was the effect of black cohosh or placebo on vasomotor symptoms severity, using the FDA and Green climacteric vasomotor scale for both hot flashes and night sweats. For daytime hot flashes, a score of 1 = mild, without sweating. A score of 2 = average sensation of heat with sweating but no interruption of daily task functions. A score of 3 = severe, extra intense sensation of heat and sweating with dysfunction and interruption of daily tasks. For night sweats, 1= mild and they do not wake the woman up and only wake up if they realize they are sweating; 2 = average, they wake up due to heat and sweating but no change of clothing or sheets is needed; 3= severe and they wake up due to heat and sweating and do need to change their cloths or get out of bed or open windows. A minimum Green vasomotor score is 1 and the maximum is 6. There was a considerable decline in vasomotor symptom severity and number of hot flashes after 4 weeks and 8 weeks in particular, compared with placebo.
Commentary: Vasomotor symptoms are seen in approximately 75% of perimenopausal and postmenopausal women and can last from 1-10 years and even more than 10 years for some women. Hot flashes can not only be very uncomfortable if moderate to severe, they can make many women anxious, self-conscious in their work environment and can significantly interfere with sleep resulting in fatigue, poor cognitive function and labile moods. Treating the vasomotor symptoms successfully can improve and potentially even alleviate all these issues. This is not the first study where I’ve run into these very low doses of extracts of an herb, and it is difficult comparing them to products in the U.S.
Shahnazi M, Nahaee J, Moammad-Alizadeh-Charandabi S, Bayatipayan S. Effects of black cohosh on vasomotor symptoms in postmenopausal women: A randomized clinical trial. J Caring Sciences 2013;2(2):105-113