Black Cohosh and Your Liver: What the Case Reports Show, and Why the Hot Flash Trials Came Up Empty
Black cohosh is the best-known herb for hot flashes. Year-long trials found it no better than placebo, and liver injury reports led the US Pharmacopeia to call for a warning label. Here is what is known, what is not, and who should skip it.
By Kymata Health Editorial Published Last checked
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What this article covers
1 evidence profileKey takeaways
From 8 sources- At least 83 cases of liver damage, from raised liver enzymes to liver failure, have been reported worldwide with black cohosh, although a causal link has not been shown1.
- A US Pharmacopeia expert review rated all 30 liver-damage reports it analyzed as possibly caused by black cohosh, none as probable or certain, and still called for a cautionary label2.
- In a 12-month trial of 351 women, 160 mg a day of black cohosh did no better than placebo for hot flashes and night sweats, while hormone therapy cut about 4 symptoms a day3.
- A Cochrane review of 16 trials in 2,027 women found insufficient evidence to support black cohosh; in the 3 trials that compared daily hot flushes with placebo (393 women), there was no difference4.
- The 2023 nonhormone therapy position statement does not recommend supplements or herbal remedies for hot flashes6.
The evidence, graded
Pulled from the trial tables in our evidence profiles. Grades follow our evidence-grading policy.
Graded findings
3 rows- ∅No effectHot flash frequency and menopausal symptom scoresNo effect No difference vs placebo in daily hot flushes (MD 0.07 per day; 3 trials, 393 women) or symptom scores (4 trials, 357 women). Hormone therapy did better than black cohosh. Authors found insufficient evidence to support or oppose use.Black cohosh · Systematic review · n=2,027 · 2012 · PMID 22972105
- ∅No effectHot flashes and night sweatsNo effect Hot flashes and night sweats per day and their intensity did not differ from placebo at 3, 6 or 12 months; hormone therapy cut about 4 symptoms per day vs placebo.Black cohosh · RCT · n=351 · 2006 · PMID 17179056
- ∅No effectHot flashes and night sweatsNo effect Symptoms fell in all groups, but black cohosh and red clover did not differ from placebo; symptom intensity was worse with black cohosh at 6 and 9 months.Black cohosh · RCT · n=89 · 2009 · PMID 19609225
The liver question: what has been reported
The NIH Office of Dietary Supplements counts at least 83 reported cases of liver damage worldwide associated with black cohosh, including hepatitis, liver failure and raised liver enzymes1. It also says there is no evidence of a causal relationship, and that impurities, adulterants or the wrong Actaea species may explain some cases, although no one independently tested the products involved1.
In 2008, an expert committee of the US Pharmacopeia reviewed 30 non-duplicate liver-damage reports with a standard causality scale2. All 30 were rated possible, none probable or certain, and the committee decided black cohosh products should carry a cautionary statement, reversing its 2002 decision that none was needed2. The recommended wording tells people to stop and see a clinician if they have a liver disorder or develop abdominal pain, dark urine or jaundice1.
Australia has required a liver warning on black cohosh products since 2007, while the FDA does not require one on US supplement labels1. Case reports continue: in 2021, doctors described a 50-year-old woman with severe jaundice after using black cohosh for menopause symptoms, whose liver tests returned to normal 6 months after she stopped5.
Does it work for hot flashes? The year-long trials say no
Two year-long trials compared black cohosh with placebo and with hormone therapy for a full year:
- Washington State, 2006: 351 women aged 45 to 55 took 160 mg a day of black cohosh, a multi-herb blend, the blend plus soy foods, hormone therapy or placebo3. Hot flashes and night sweats on the herbal regimens did not differ from placebo at 3, 6 or 12 months, while hormone therapy cut about 4 symptoms a day versus placebo3.
- Chicago, 2009: 89 women took 128 mg a day of standardized black cohosh, red clover, hormone therapy or placebo for 12 months7. Symptoms fell 34% on black cohosh, 57% on red clover, 63% on placebo and 94% on hormone therapy, and only hormone therapy differed from placebo7. ODS notes that symptom intensity was worse on black cohosh than on placebo at 6 and 9 months1.
What the pooled evidence shows
The 2012 Cochrane review pooled 16 randomized trials in 2,027 women, at a median 40 mg a day for an average of 23 weeks4. Black cohosh did not differ from placebo for daily hot flushes (3 trials, 393 women) or menopause symptom scores (4 trials, 357 women), and hormone therapy did better than black cohosh4. The reviewers rated the safety evidence inconclusive because side effects were poorly reported4.
An earlier meta-analysis that included products combining black cohosh with other ingredients reported a 26% improvement in vasomotor symptoms, with significant differences between trials8. Mixing products makes that figure hard to apply to any single bottle.
Expert groups have reached the same view. The 2023 nonhormone position statement lists supplements and herbal remedies as not recommended, and recommends options such as cognitive behavioral therapy, clinical hypnosis, SSRIs or SNRIs, gabapentin and fezolinetant6. Our non-hormonal hot flash options and the wider menopause supplements review cover these in more depth, and the menopause hub starts with the basics.
Who should avoid black cohosh
In trials, black cohosh caused few side effects, most often mild stomach upset and rash, but most studies lasted 6 months or less, so long-term safety is unknown1. ODS lists no known clinically relevant drug interactions, while noting that interactions have not been studied systematically1. Groups that should avoid it or check with a clinician first:
- Liver disease or liver symptoms: the US Pharmacopeia advises people with liver disorders to avoid black cohosh, and anyone who develops abdominal pain, dark urine or jaundice to stop and contact a doctor1.
- Pregnancy: the American Herbal Products Association advises against use except under a clinician’s supervision, because use in pregnancy has not been rigorously studied1.
- Breast cancer survivors and others told to avoid estrogen: ODS says studies disagree on whether black cohosh raises estrogen levels, and its effects on uterine and vaginal tissue are unclear1, so this is a question for the cancer care team.
- Multi-herb menopause blends: in the 2006 trial, a blend containing black cohosh plus soy made symptom intensity worse than placebo at 12 months3.
- Product quality: preparations vary widely in chemical makeup, and ODS notes some liver cases may have involved adulterants or the wrong species1. The black cohosh page lists the studied extracts and doses, and our turmeric liver-safety article covers another herb with liver reports.
Quick answers
Common questions
4 answersDoes black cohosh cause liver damage?
How long can you take black cohosh?
Most studies lasted 6 months or less, so long-term safety in humans is unknown1.
What works better than black cohosh for hot flashes?
Hormone therapy remains the most effective treatment, and the 2023 statement recommends nonhormone options including cognitive behavioral therapy, SSRIs or SNRIs, gabapentin and fezolinetant6.
Is black cohosh a form of estrogen?
No. Its active compounds and mechanism are unknown, and studies disagree on whether it has estrogen-like effects1.
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Where to buy Black cohosh
Products from brands we partner with that contain Black cohosh. Check the amount per serving against the doses studied, and the label for other ingredients.
Black cohosh products from partner brands
1 product Paid links · we earn a commission- HerbsProNature's Way Black Cohosh Root, 540 mg, 100 Caps
1 capsule: 540 mg black cohosh (root), not a standardized extract
$14.99one-timeChecked Oct 15, 2026
References
8 sources. Numbers in the text link here.
Sources cited in this article
8 sources- 1Black Cohosh: Fact Sheet for Health ProfessionalsNIH Office of Dietary Supplements, 2020
- 2United States Pharmacopeia review of the black cohosh case reports of hepatotoxicityMenopause, 2008 · PMID 18340277
- 3Treatment of vasomotor symptoms of menopause with black cohosh, multibotanicals, soy, hormone therapy, or placebo: a randomized trialAnn Intern Med, 2006 · PMID 17179056
- 4Black cohosh (Cimicifuga spp.) for menopausal symptomsCochrane Database Syst Rev, 2012 · PMID 22972105
- 5Case of cholestatic drug-induced liver injury (DILI) associated with black cohoshBMJ Case Rep, 2021 · PMID 33962922
- 6The 2023 nonhormone therapy position statement of The North American Menopause SocietyMenopause, 2023 · PMID 37252752
- 7Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trialMenopause, 2009 · PMID 19609225
- 8Efficacy of black cohosh-containing preparations on menopausal symptoms: a meta-analysisAltern Ther Health Med, 2010 · PMID 20085176
Black cohosh and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. Product links on this page are paid partner links.