From the Guidelines
Black cohosh is not recommended for treating hot flashes due to its lack of efficacy and potential safety risks, including liver failure. The most recent and highest quality study, published in 2017 1, found limited data to support the use of black cohosh for vasomotor symptoms in the general population, and randomized data in breast cancer survivors showed no benefit. Additionally, a 2008 study 1 reported several cases of liver failure associated with black cohosh use.
Key Considerations
- The efficacy of black cohosh in reducing hot flashes is not supported by strong evidence, with some studies showing no benefit 1.
- Safety concerns, including liver failure, have been reported with black cohosh use 1.
- Alternative non-pharmacologic treatments, such as acupuncture, exercise, and cognitive behavioral therapy, may be effective in managing hot flashes 1.
- Vitamin E has shown limited efficacy in reducing hot flashes, but high doses (>400 IU/day) may increase all-cause mortality 1.
Clinical Implications
- Given the lack of efficacy and potential safety risks, black cohosh should not be recommended as a treatment for hot flashes.
- Healthcare providers should consider alternative treatments, such as non-pharmacologic interventions, and carefully weigh the risks and benefits of any therapy.
- Patients should be informed of the potential risks and limitations of black cohosh and other complementary therapies.
From the Research
Recommended Dose of Black Cohosh
The recommended dose of black cohosh (Cimicifuga racemosa) for treating hot flashes (vasomotor symptoms) is:
- 40-80 mg per day, as stated in the study 2
- Some studies used a specific dose, such as 20 mg twice a day, as mentioned in the study 3
- The median daily dose used in 16 randomised controlled trials was 40 mg, as reported in the study 4
Treatment Duration
- At least 4-12 weeks of treatment may be required before any therapeutic benefits may be apparent, as stated in the study 2
- Some studies had a treatment duration of 4 weeks, as mentioned in the studies 3 and 5
Efficacy of Black Cohosh
- The efficacy of black cohosh for treating hot flashes is inconclusive, with some studies showing a reduction in hot flash frequency and others showing no significant difference compared to placebo, as reported in the studies 3, 5, and 4
- Black cohosh may have a low toxicity profile, with minimal adverse effects reported in some studies, as mentioned in the studies 2, 3, and 5