Black Cohosh: Benefits, Risks, and the Truth Behind the Root

A Historical Look

Black cohosh is a native plant of the eastern woodlands. Due to forest loss in the Northeast and overharvesting, it has become increasingly rare in the wild and is now listed on the United Plant Savers endangered list.

The root and rhizome are the parts used for medicine. When dug from the earth, the root appears black. The word “cohosh” comes from the Algonquian language and translates to “rough,” describing the root’s appearance.

Long before European settlers arrived, tribes of the Northeast valued black cohosh for a wide range of ailments—joint pain (rheumatism), snake bites, pregnancy-related complications, and menstrual complaints. Traditionally, it was used in a more diverse and creative way than it is today.

👉 You can explore the North American Ethnobotany database for a full list of uses: naeb.brit.org (search Actaea racemosa).

Today, black cohosh is best known in the West as a menopause remedy.

Does Black Cohosh Work?

That depends on what you’re trying to address. No herb works for everyone’s menopausal symptoms, but black cohosh is the most studied herbal remedy for hot flashes specifically.

It may not help women whose menopause is caused by chemotherapy or hysterectomy, but it is often effective for hot flashes, night sweats, and other temperature regulation issues.

One big reason people don’t see results? Poor-quality or adulterated products. A review of 322 samples found that 42.2% of black cohosh products were adulterated (substituted with other herbs).

How Does Black Cohosh Work?

Unlike other herbs for hot flashes, such as Siberian rhubarb (Rheum rhaponticum) or maca, black cohosh’s effects are likely not due to phytoestrogens (plant compounds that mimic estrogen) but rather other effects.

Researchers believe its effects may instead be due to serotonergic and dopaminergic activity (EMA, 2018). 

It is important to remember that neural pathways impact temperature regulation in the body.  Declining estrogen affects serotonin levels, which in turn influence body temperature regulation.

What Does the Research Say?

Research on black cohosh is strong when it comes to menopausal symptoms. One of the best compilations was a  meta-analysis of 22 randomized controlled trials (included 2,310 participants) found mild to moderate benefits for hot flashes and overall menopausal symptoms—but not for anxiety or depression (Sadahiro et al., 2023).

A combination product with St. John’s Wort (Remifemin Plus) showed greater benefits for mood-related symptoms (Briese et al., 2007; Uebelhack et al., 2006).

Evidence is less clear on whether black cohosh supports bone health or helps with medically-induced menopause.

How to Take Black Cohosh

Most clinical research—especially in Germany—used relatively small doses:  5.0–6.5 mg dry extract/day (solvent: ethanol or isopropanol); Equivalent to about 40 mg crude herb (EMA, 2018).  

Please note there are MANY products on the market with doses ranging up to 1200 mg.  For the purpose of menopausal hot flashes, there is no need to take a dose higher than 40 mg total per day.

In studies this was adminstered as a standardized extract. Traditionally, larger doses and tinctures were used.

One of the best-studied products is Remifemin (Medice, Germany), also packaged in the U.S. by Nature’s Way.

👉 Pro tip: Herbs absorb best before meals. For example, I often recommend Remifemin, 1 capsule twice daily before meals.

Is Black Cohosh Safe?

The main safety concern is adulterated products. Always buy from high-quality suppliers that use third-party testing to verify that they are using the correct plant!

There are rare but serious cases of idiosyncratic liver toxicity. Most evidence suggests these are due to adulteration rather than black cohosh itself (Black Cohosh, 2025).  Please see note above on dosing.  I recommend staying under 40 mg total dose a day.  Many products provide higher doses.

American Herbal Products Association (AHPA) issued this statement in response to New Zealand creating new warning labels for black cohosh.

"A U.S. National Institutes of Health workshop on black cohosh safety in clinical trials, held in November 2004 concluded that the evidence for liver toxicity risks from black cohosh "remains equivocal but certainly warrants continued monitoring.”

NIH stated” At this time, there is no known mechanism with biological plausibility that explains any hepatotoxic activity of black cohosh." The NIH reviewed information on 51 adverse events.

Key points on safety and dosing:

• Always inform all health professionals about your supplement intake

• Stay under 40 mg a day total dose, 6.5 mg 2 x daily is preferred

• Use reputable suppliers that use 3rd party testing to avoid adulteration

• Avoid this herb if you have liver disease or are taking medications that challenge liver function

• Remifemin is the product Rebecca recommends

References

Black cohosh. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. Updated April 15, 2025. Accessed at ncbi.nlm.nih.gov/books/NBK547990/ on April 29, 2025.

Briese, V., Stammwitz, U., Friede, M., & Henneicke-von Zepelin, H. H. (2007). Black cohosh with or without St. John's wort for symptom-specific climacteric treatment--results of a large-scale, controlled, observational study. Maturitas, 57(4), 405–414.

[EMA] European Medicines Agency. (2018). Final assessment report on Cimicifuga racemosa (L.) Nutt., rhizome – Revision 1. Amsterdam (NL): European Medicines Agency.

Felter, H.W. (1922). The eclectic materia medica, pharmacology and therapeutics. Portland (OR): Eclec Med Pub. Reprint edition 1985.

Orhan N, Gafner S, Blumenthal M. Estimating the extent of adulteration of the popular herbs black cohosh, echinacea, elder berry, ginkgo, and turmeric - its challenges and limitations. Nat Prod Rep. 2024 Oct 17;41(10):1604-1621. doi: 10.1039/d4np00014e. PMID: 39108221.

Sadahiro, R., Matsuoka, L. N., Zeng, B. S., Chen, K. H., Zeng, B. Y., Wang, H. Y., Chu, C. S., Stubbs, B., Su, K. P., Tu, Y. K., Wu, Y. C., Lin, P. Y., Chen, T. Y., Chen, Y. W., Suen, M. W., Hopwood, M., Yang, W. C., Sun, C. K., Cheng, Y. S., Shiue, Y. L., … Tseng, P. T. (2023). Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis. Menopause (New York, N.Y.), 30(7), 766–773.

Uebelhack, R., Blohmer, J. U., Graubaum, H. J., Busch, R., Gruenwald, J., & Wernecke, K. D. (2006). Black cohosh and St. John's wort for climacteric complaints: a randomized trial. Obstetrics and gynecology, 107(2 Pt 1), 247–255.