Actaea racemosa L.

A. monogyna Walter; Cimicfuga racemosa (L.) Nutt.

Ranunculaceae

black snakeroot; bugbane; bugwort; Macrotys; rattleweed; squawroot

Cimicifugae racemosae rhizoma

Rhizomes, roots

The main active constituents are the triterpene glycosides, a great number of which have been reported and include actein, 27-deoxyactein, a series of cimicifugosides and the cimiracemosides. Polyphenolic compounds such as the cimiracemates, caffeic acid derivatives, ferulic and isoferulic acids, fukinolic acid and cimicifugic acids, quinolizidine alkaloids and other compounds are also present (Foster 2013; Williamson et al. 2013).

Most of the clinical studies have been carried out on standardised extracts (e.g. ZE450 and CR BNO 1055).

A Cochrane review evaluated the clinical effectiveness and safety of black cohosh in treating menopausal symptoms in peri-menopausal and post-menopausal women. The review identified 16 randomised controlled trials, with 2027 women, which used a median daily dose of 40 mg of black cohosh, for a mean duration of 23 weeks. The results of the review showed that there was no significant statistical difference between black cohosh and placebo in the frequency of hot flushes, or menopausal symptom scores. However, while the authors conclude there is insufficient clinical evidence to support the use of black cohosh to treat menopausal symptoms, study results were mixed, with some studies suggesting that black cohosh may help in relieving menopausal symptoms. Variability in study design and levels of active constituents in phytopharmaceutical products may explain the inconsistencies found in the different studies, especially since only six of the studies were standardised to between 2.5% and 5.68% triterpene glycosides (Leach and Moore 2012).

A randomised, double-blind, placebo-controlled study in 80 menopausal women not included in Leach and Moore (2012) compared 8 mg/day of a black cohosh extract with placebo or conjugated oestrogens. At 12 weeks menopausal symptoms, including hot flushes, were significantly lower in the treated groups than the placebo group, with the black cohosh group scoring better than the oestrogen treatment (Warnecke 1985 summarised in NIH 2008).