Black cohosh
A Cochrane review found no difference from placebo in hot flash frequency or menopause scores. A 2023 meta-analysis found improvements, and year-long US trials found none. Liver injury has been reported, including liver failure and transplants. Regulators in the UK, EU and Australia added liver warnings. Some products contained other Actaea species.
Add to Bio HackChecked 2026-11-09
- Status
- Dietary supplement in the US. Licensed as a herbal medicine in the EU and UK, where product information warns of rare liver reactions. Australia requires a liver warning on labels.
- Also called
- Actaea racemosa, Cimicifuga racemosa, black snakeroot, bugbane, rattleweed, iCR, isopropanolic black cohosh extract, Remifemin
- Taken for
- hot flashes, night sweats, menopause symptoms, mood during menopause, hot flashes after breast cancer
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help0
No benefit shown in research yet.
Reported risks4
- ModerateCase reports: hepatitis, jaundice and liver failure needing transplant were reported, mostly within 3 months. Experts rated the cases possibly caused by black cohosh.
- ModerateThe Australian label warns black cohosh may harm the liver in some individuals. UK, EU and US Pharmacopeia bodies also require liver warnings.
- LimitedLimited evidence: product tests found 4 of 11 US products contained Asian Actaea species, and Japanese products contained other Cimicifuga species.
- LimitedThe EU herbal committee lists allergic skin reactions, swelling of the face and limbs, indigestion and diarrhea, at unknown frequency.
What people take it for, and what was found
Mixed results2
Hot flashes
Mixed results: a Cochrane review and two 1-year trials found no benefit over placebo for hot flashes, while a 2023 review found fewer hot flashes.
The numbers and sources
- Effect
- A Cochrane review of 16 trials (2,027 women) found no difference from placebo in daily hot flashes (MD 0.07 a day, 95% CI -0.43 to 0.56, 3 trials) [1]. A 2023 meta-analysis of 22 articles (2,310 women) found fewer hot flashes than placebo (Hedges' g 0.315, 95% CI 0.107 to 0.524) [2]. In a 1-year US trial of 351 women, 160 mg a day did not differ from placebo at any time point, while hormone therapy lowered symptoms by 4.06 a day [3]. In another 1-year trial, symptoms fell 34% on black cohosh and 63% on placebo [4].
- Population
- Perimenopausal and postmenopausal women [1][2][3][4].
- Sources
- [1], [2], [3], [4]
- Caveats
- The sources disagree. The Cochrane review rated trial quality as generally unclear [1]. [3] was funded by NIA and [4] by NCCIH.
Overall menopause symptom scores
Mixed results: the Cochrane review found no difference from placebo in menopause symptom scores, while a 2023 review and studies of one extract found improvement.
The numbers and sources
- Effect
- The Cochrane review found no difference from placebo in symptom scores (SMD -0.10, 95% CI -0.32 to 0.11, 4 trials, 357 women), and hormone therapy reduced scores more than black cohosh [1]. The 2023 meta-analysis found improved overall scores (g 0.575, 95% CI 0.283 to 0.867) [2]. A review of the isopropanolic extract iCR, pooling 35 studies, reported an SMD of -0.694 against placebo [5].
- Population
- Menopausal women [1][2]. Studies of one proprietary extract [5].
- Sources
- [1], [2], [5]
- Caveats
- [5] covered a single commercial extract. The Cochrane review contacted manufacturers for data [1].
Not shown to help2
Hot flashes after breast cancer
One trial found black cohosh did not reduce hot flashes more than placebo over 4 weeks in 132 women with or after breast cancer.
The numbers and sources
Anxiety and depression in menopause
Limited evidence: anxiety and depressive symptoms did not improve significantly against placebo in the few trials that measured them.
The numbers and sources
Doses studied
Cochrane trials used a median of 40 mg a day for a mean of 23 weeks [1]. The 1-year US trial used 160 mg a day [3], and the breast cancer trial 20 mg twice a day [6]. Trials of the isopropanolic extract used the equivalent of 40 to 128 mg of herb a day for 3 to 6 months [7].
Risks
Reported risks4
Liver injury
Case reports: hepatitis, jaundice and liver failure needing transplant were reported, mostly within 3 months. Experts rated the cases possibly caused by black cohosh.
The numbers and sources
- Effect
- A US Pharmacopeia expert committee reviewed 30 non-duplicate reports of liver damage and rated all as possibly caused by black cohosh, none as probable or certain [8]. The UK regulator received 21 reports of liver reactions by March 2006. Of 39 reports from the UK, Germany, Sweden, the US and the literature, 21 people were admitted to hospital. One UK patient needed a liver transplant. Reported reactions included hepatitis, jaundice and liver failure requiring transplant, mostly within the first 3 months [9].
- Population
- Spontaneous reports and published cases [8][9].
- Sources
- [8], [9]
- Caveats
- Case reports cannot give a rate. Some cases were confounded by other products or medicines [9].
Regulator label warnings
The Australian label warns black cohosh may harm the liver in some individuals. UK, EU and US Pharmacopeia bodies also require liver warnings.
The numbers and sources
- Effect
- In 2006, after assessing 47 cases, Australia required labels to state: "Black cohosh may harm the liver in some individuals. Use under the supervision of a healthcare professional" [9]. UK expert committees concluded the evidence supports an association with liver toxicity and had warnings about rare liver reactions added to all black cohosh product information [9]. The EU herbal committee lists liver problems as a side effect, and its summary tells users to stop and see a doctor if signs of liver problems appear [10]. The US Pharmacopeia decided black cohosh products are to be labeled with a cautionary statement [8].
- Population
- Products sold in Australia, the UK, the EU and the US [8][9][10].
- Sources
- [9], [10], [8]
- Caveats
- The Australian wording is as quoted by the UK regulator in 2006 [9]. The current Australian wording was not checked for this page.
Wrong plant in the bottle
Limited evidence: product tests found 4 of 11 US products contained Asian Actaea species, and Japanese products contained other Cimicifuga species.
The numbers and sources
- Effect
- Of 11 US black cohosh products tested, 3 contained Asian Actaea species instead of black cohosh, and 1 contained both [12]. In Japan, genetic and chemical tests found products made from Cimicifuga dahurica and possibly C. foetida, and black cohosh extracts mixed with C. dahurica [13].
- Population
- Commercial products [12][13].
- Sources
- [12], [13]
- Caveats
- Small product samples. Whether misidentified plants explain the liver cases was not tested here.
Other side effects
The EU herbal committee lists allergic skin reactions, swelling of the face and limbs, indigestion and diarrhea, at unknown frequency.
The numbers and sources
- Effect
- The EU herbal committee lists allergic skin reactions, swelling of the face and limbs, indigestion and diarrhea, with unknown frequency [10]. The UK report notes that large doses have been linked to gut irritation, headache, dizziness and vomiting [9].
- Population
- Users of licensed herbal products [9][10].
- Sources
- [10], [9]
- Caveats
- Regulatory summaries without rates.
Checked, no increase found1
Liver tests in trials
Limited evidence: liver enzymes did not differ from comparison groups in 5 trials of one extract, though trials this size cannot detect rare reactions.
The numbers and sources
- Effect
- In 5 trials (1,117 women) of the isopropanolic extract for 3 to 6 months, AST and ALT did not differ between black cohosh and comparison groups [7]. A 1-year trial found no safety concerns in its monitoring [4].
- Population
- Perimenopausal and postmenopausal women [7][4].
- Sources
- [7], [4]
- Caveats
- Trials of hundreds of women cannot detect a rare reaction. [7] covered one proprietary extract. In a systematic review of 14 black cohosh trial reports, adherence to the CONSORT checklist for reporting harms ranged from 6% to 90%, and 3 reports scored 50% or less [11].
Claims tested and not found
- That black cohosh reduces hot flashes after breast cancer. Scores and frequency did not differ from placebo [6].
- That black cohosh reduces hot flashes over a year. Two 1-year trials found no difference from placebo [3][4].
- That black cohosh eases anxiety or depression in menopause. Pooled effects were not significant [2].
Sources
- Leach MJ, Moore V. Black cohosh (Cimicifuga spp.) for menopausal symptoms. Cochrane Database of Systematic Reviews. 2012. https://doi.org/10.1002/14651858.CD007244.pub2
- Sadahiro R, Matsuoka LN, Zeng BS, et al. Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis. Menopause. 2023. https://doi.org/10.1097/gme.0000000000002196
- Newton KM, Reed SD, LaCroix AZ, et al. Treatment of Vasomotor Symptoms of Menopause with Black Cohosh, Multibotanicals, Soy, Hormone Therapy, or Placebo: A Randomized Trial. Annals of Internal Medicine. 2006. https://doi.org/10.7326/0003-4819-145-12-200612190-00003
- Geller SE, Shulman LP, van Breemen RB, et al. Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trial. Menopause. 2009. https://doi.org/10.1097/gme.0b013e3181ace49b
- Castelo-Branco C, Gambacciani M, Cano A, et al. Review & meta-analysis: isopropanolic black cohosh extract iCR for menopausal symptoms, an update on the evidence. Climacteric. 2021. https://doi.org/10.1080/13697137.2020.1820477
- Pockaj BA, Gallagher JG, Loprinzi CL, et al. Phase III Double-Blind, Randomized, Placebo-Controlled Crossover Trial of Black Cohosh in the Management of Hot Flashes: NCCTG Trial N01CC1. Journal of Clinical Oncology. 2006. https://doi.org/10.1200/jco.2005.05.4296
- Naser B, Schnitker J, Minkin MJ, et al. Suspected black cohosh hepatotoxicity: no evidence by meta-analysis of randomized controlled clinical trials for isopropanolic black cohosh extract. Menopause. 2011. https://doi.org/10.1097/gme.0b013e3181fcb2a6
- Mahady GB, Low Dog T, Barrett ML, et al. United States Pharmacopeia review of the black cohosh case reports of hepatotoxicity. Menopause. 2008. https://doi.org/10.1097/gme.0b013e31816054bf
- Medicines and Healthcare products Regulatory Agency. Black Cohosh: UK Public Assessment Report. 2006. https://assets.publishing.service.gov.uk/media/5df7610ce5274a08f78bca34/Black_cohosh_and_liver_injury.pdf
- European Medicines Agency. Black cohosh, Cimicifuga racemosa (L.) Nutt., rhizoma: summary for the public. EMA/265439/2018. 2018. https://www.ema.europa.eu/en/documents/herbal-summary/black-cohosh-summary-public_en.pdf
- Curtis S, Moore A, Breakspear I. Efficacy and safety of Actaea racemosa for relieving climacteric complaints. Menopause. 2026. https://doi.org/10.1097/gme.0000000000002704
- Jiang B, Kronenberg F, Nuntanakorn P, et al. Evaluation of the Botanical Authenticity and Phytochemical Profile of Black Cohosh Products by High-Performance Liquid Chromatography with Selected Ion Monitoring Liquid Chromatography-Mass Spectrometry. Journal of Agricultural and Food Chemistry. 2006. https://doi.org/10.1021/jf0606149
- Masada-Atsumi S, Kumeta Y, Takahashi Y, et al. Evaluation of the Botanical Origin of Black Cohosh Products by Genetic and Chemical Analyses. Biological and Pharmaceutical Bulletin. 2014. https://doi.org/10.1248/bpb.b13-00844