Black Cohosh

botanicalcarbon black

What is it

Black cohosh (Actaea racemosa, formerly Cimicifuga racemosa) is a perennial plant from the buttercup family native to North America. Its roots and rhizomes have been used historically by Native Americans for musculoskeletal pain, fever, and women's reproductive health, and today it is most commonly marketed for menopausal symptoms.

How it works

The active ingredients in black cohosh remain unknown. Preparations are typically standardized to triterpene glycosides such as actein, 23-epi-26-deoxyactein, and cimicifugoside, but the specific compounds responsible for any symptom relief have not been definitively identified. Other potential active substances include resins like cimicifugin and aromatic acid derivatives including caffeic, isoferulic, and fukinolic acids. Studies of black cohosh's effects on human physiology have produced inconsistent results regarding whether it raises estrogen levels, affects luteinizing hormone or follicle-stimulating hormone, or impacts vaginal and uterine tissue. Despite frequent classification as a 'phytoestrogen,' direct estrogenic effects are not well established. Some researchers have proposed that black cohosh may work through brain-related mechanisms, including modulation of serotonergic pathways or potential antioxidant, anti-inflammatory, or selective estrogen receptor modulator activity. The mechanism remains an active area of investigation, and absence of a clear mechanism complicates interpretation of clinical findings.

Evidence for 3 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Menopausal hot flashes and night sweats

Grade D

Mixed evidence

A 2012 Cochrane Review of 16 randomized clinical trials with 2,027 women concluded there was insufficient evidence to support or oppose black cohosh use for menopausal symptoms. A 2016 systematic review and meta-analysis found no significant associations between black cohosh and vasomotor symptom reduction. The American College of Obstetricians and Gynecologists and the North American Menopause Society do not recommend it for hot flashes.

Other menopausal symptoms (sleep, mood, vaginal dryness)

Grade D

Mixed evidence

Studies have investigated secondary endpoints including insomnia, fatigue, depression, anxiety, and vaginal dryness. For most outcomes, no significant differences appeared between black cohosh and placebo at any time.

Musculoskeletal pain and women's reproductive health (traditional uses)

Grade F

Limited evidence

Native American historical uses included musculoskeletal pain, fever, cough, pneumonia, sluggish labor, and menstrual irregularities. These traditional uses lack rigorous modern clinical evidence.

4 commercial forms

Standardized root and rhizome extract

Often standardized to triterpene glycoside content

Most common form in supplements. Standardization varies; some products use 2.5% to 5.7% triterpene glycosides.

Remifemin (proprietary extract)

Standardized to be equivalent to 40 mg root/rhizome per daily dose

Commercial product used in many clinical studies. Has been reformulated multiple times.

Dried root/rhizome powder

Variable composition

Traditional whole-herb form. Composition and potency vary widely between products.

Liquid extract / tincture

Alcohol-based extraction

Used in traditional preparations. Varies in concentration and standardization.

Dosage

There is no established RDA. Products containing black cohosh extract are frequently standardized to provide at least 1 mg of triterpene glycosides per daily dose. Remifemin, a commercial product used in several clinical studies, is standardized to be equivalent to 40 mg black cohosh root/rhizome per daily dose (two tablets), though it is not standardized to triterpene glycoside content. Clinical trials have used 6.5 to 160 mg per day (median 40 mg per day).

When and how to take it

Black cohosh is typically taken once or twice daily for menopausal symptoms. It can be taken with or without food, though taking with food may reduce mild gastrointestinal effects. Effects on menopausal symptoms, when present, typically emerge over weeks to a few months rather than acutely. Most trials have run 6 to 12 months. Long-term continuous use beyond 6 months has not been well studied for safety.

Safety

Clinical trials using various black cohosh preparations show low adverse effect incidence. The most commonly reported side effects are gastrointestinal upset and rashes, both mild and transient. Other reported effects include breast pain or enlargement, infection, vaginal bleeding or spotting, and musculoskeletal complaints, with incidence generally similar to placebo. Most studies examined short-term use (typically 6 months or less), so long-term human safety is not well established. Worldwide reports describe at least 83 liver damage cases associated with black cohosh use, including hepatitis, liver failure, and elevated liver enzymes, though no causal relationship has been established. Some cases may have resulted from impurities or incorrect species in products.

Who should be cautious

The American Herbal Products Association recommends pregnant women avoid black cohosh except under healthcare provider supervision, because use in pregnancy has not been rigorously evaluated. The U.S. Pharmacopeia advises individuals with liver disorders to avoid black cohosh and recommends users developing symptoms of liver trouble (abdominal pain, dark urine, jaundice) discontinue use and contact their doctor. Australia requires liver-injury warning labels on black cohosh products. The North American Menopause Society advises clinicians against recommending black cohosh because it is unlikely to be beneficial for vasomotor symptoms.

Interactions

Black cohosh is not known to have any clinically relevant medication interactions, although this has not been systematically studied. Given case reports of liver injury, theoretical concerns exist about combining with other hepatotoxic medications or supplements. Discuss with a clinician if you take medications metabolized by the liver.

Frequently asked questions

Does black cohosh actually work for hot flashes?⌄

Available evidence is inconsistent. A 2012 Cochrane Review and a 2016 meta-analysis both concluded there is insufficient or no significant evidence that black cohosh reduces hot flashes more than placebo. Major medical organizations including the North American Menopause Society do not recommend it.

Is black cohosh safe for my liver?⌄

Worldwide reports describe at least 83 cases of liver damage associated with black cohosh use, though causation has not been established. Some cases may have involved impurities or incorrect species. People with liver disease should avoid it, and anyone developing symptoms of liver trouble should stop and contact a doctor.

Is black cohosh estrogenic?⌄

Despite common claims, studies on whether black cohosh raises estrogen levels or has direct estrogenic effects are inconsistent. The mechanism remains unclear, and it is not equivalent to estrogen therapy.

Is black cohosh safe in pregnancy?⌄

No. The American Herbal Products Association recommends pregnant women avoid black cohosh except under healthcare provider supervision. Use in pregnancy has not been rigorously evaluated.

How long can I take black cohosh?⌄

Most studies examined short-term use (typically 6 months or less), so long-term safety is not established. Discuss extended use with your healthcare provider, especially given liver injury concerns.

References

Black Cohosh - Health Professional Fact Sheet — NIH Office of Dietary Supplements link
ChEBI: carbon black — ChEBI Database link
Wikidata: Actaea racemosa — Wikidata link

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.