NutriDex

The Supplement Research Compendium
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Black Cohosh

Actaea racemosa

Popular menopause herb for hot flashes — but trials disagree.

Mixed evidence 🌙Sleep & Mood

✚ Updated · How we grade evidence

Evidence tier
Mixed
Research weight
Citations
7 verified / 7
Classification
Sleep & Mood
❝
What the evidence says. Graded mixed: the rigorous Cochrane review of 16 RCTs (n=2,027) and the largest independent NIH-funded trials found no benefit over placebo, while several smaller trials and industry-linked meta-analyses of one branded extract report real symptom relief — so results genuinely conflict and depend heavily on the product studied. (Mixed evidence: Conflicting results across studies; benefit uncertain.)

What is Black Cohosh?

Black Cohosh (Actaea racemosa) is a sleep and mood supplement used for menopausal hot flashes. NutriDex grades the human evidence as Mixed. Black cohosh is a North American woodland rhizome marketed for menopausal symptoms, especially hot flashes. The evidence is genuinely split. A 2012 Cochrane review of 16 randomized trials (2,027 women) found no significant difference from placebo in hot-flash frequency or symptom scores, and large NIH-funded trials such as Geller 2009 were null (34% reduction with black cohosh vs 63% with placebo over 12 months). Yet a 2010 meta-analysis reported a 26% improvement in vasomotor symptoms (95% CI 11–40%), and industry-linked meta-analyses of one isopropanolic extract (iCR) claim a moderate-to-large effect (SMD ~-0.69). Effects, when seen, are modest and the herb is not estrogenic. It is not a substitute for hormone therapy. Quality varies widely between products, which partly explains the inconsistent results.

Purported Benefits

✓Menopausal hot flashes
✓Night sweats
✓Menopausal mood & irritability
✓Sleep disturbance in menopause

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Menopausal hot flashes / vasomotor symptomsCochrane (16 RCTs) and NIH Geller trial null; other meta-analyses show ~26% benefit with high heterogeneity and product variability. Mixed ↔ mixed 5
Menopausal mood & psychological symptomsOnly the industry-linked iCR meta-analysis (SMD -0.69) supports neurovegetative/psychological benefit; not independently confirmed. Mixed ↔ mixed 1

Dosing & Compounds

Typical Dose
20–40 mg of standardized rhizome extract once or twice daily; isopropanolic (iCR) and ethanolic extracts are the most-studied forms.
Active Compounds
Triterpene glycosides (e.g. actein, 27-deoxyactein)Cimicifugic acidsFukinolic acid

Safety & Cautions

Generally well tolerated; the most common effects are GI upset, headache, rash and mild weight gain. Rare but serious idiosyncratic liver injury — including cases of acute liver failure requiring transplant — has been reported, so stop and seek care for jaundice, dark urine, or right-upper-abdominal pain (NIH LiverTox likelihood score A). Avoid in pregnancy, breastfeeding, and active or hormone-sensitive cancers until cleared by a clinician; use caution alongside other hepatotoxic drugs, statins, acetaminophen or alcohol, and with antihypertensives or sedatives. Product quality varies, and some supplements have been adulterated with the wrong Actaea species. Educational only — always check with your doctor or pharmacist before combining Black Cohosh with any medicine.

Black Cohosh drug interactions

Known or theoretical interactions between Black Cohosh and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Black Cohosh with any medicine.

Avoid
Pregnancy
Black cohosh may not be safe during pregnancy or breastfeeding; avoid use.
Possible hormonal and uterine-stimulating activity raises safety concerns in pregnancy. NCCIH — Black Cohosh
Caution
Hormone therapy / tamoxifen
Black cohosh safety is uncertain in hormone-sensitive conditions such as breast or uterine cancer; use caution.
Black cohosh may exert tissue-selective hormonal or estrogen-modulating activity, raising concern in hormone-sensitive disease. NCCIH — Black Cohosh
Caution
Liver-stressing drugs / alcohol
Rare cases of serious liver damage have been reported with black cohosh; use caution with other liver-stressing drugs or alcohol.
Black cohosh has been linked to idiosyncratic hepatotoxicity, which may compound the burden from other hepatotoxic agents. NCCIH — Black Cohosh

Key Studies

Meta-analysis Castelo-Branco 2021 ✓ PubMed
Review/meta-analysis of isopropanolic extract (iCR): SMD -0.694 vs placebo for neurovegetative/psychological symptoms (p<0.0001); industry-linked.
Systematic review Leach 2012 (Cochrane) ✓ PubMed
16 RCTs (n=2,027): no significant difference vs placebo in hot-flush frequency or menopausal symptom scores; insufficient evidence to support use.
Meta-analysis Shams 2010 ✓ PubMed
Meta-analysis of 7 RCTs: black-cohosh preparations improved vasomotor symptoms by 26% overall (95% CI 11–40%), with significant heterogeneity.
RCT Mohammad-Alizadeh-Charandabi 2013 ✓ PubMed
Double-blind RCT (n=84): black cohosh significantly reduced number and severity of hot flashes vs placebo at weeks 4 and 8.
Safety LiverTox 2020 (NIH) ✓ Full text
Likelihood score A: >50 published cases of clinically apparent liver injury (latency 2–12 wks); causative component unclear, possibly adulterants.
RCT Geller 2009 ✓ PubMed
12-mo RCT (n=89): vasomotor symptoms fell 34% with black cohosh vs 63% placebo (NS); only conjugated estrogen/MPA beat placebo.
Review Hedaoo 2024 ✓ Full text
Review (2006–2023): black cohosh may reduce vasomotor symptoms, but dose, formulation and assessment variability preclude firm conclusions.
7 sources cited · 7 verified Search all studies on PubMed ↗

Common questions about Black Cohosh

What is Black Cohosh used for?

Black Cohosh is most often taken for Menopausal hot flashes, Night sweats, Menopausal mood & irritability, Sleep disturbance in menopause. Popular menopause herb for hot flashes — but trials disagree.

Does Black Cohosh work — what does the evidence say?

Mixed evidence. Conflicting results across studies; benefit uncertain. Black cohosh is a North American woodland rhizome marketed for menopausal symptoms, especially hot flashes. The evidence is genuinely split. A 2012 Cochrane review of 16 randomized trials (2,027 women) found no significant difference from placebo in hot-flash frequency or symptom scores, and large NIH-funded trials such as Geller 2009 were null (34% reduction with black cohosh vs 63% with placebo over 12 months). Yet a 2010 meta-analysis reported a 26% improvement in vasomotor symptoms (95% CI 11–40%), and industry-linked meta-analyses of one isopropanolic extract (iCR) claim a moderate-to-large effect (SMD ~-0.69). Effects, when seen, are modest and the herb is not estrogenic. It is not a substitute for hormone therapy. Quality varies widely between products, which partly explains the inconsistent results.

What is the typical dose of Black Cohosh?

20–40 mg of standardized rhizome extract once or twice daily; isopropanolic (iCR) and ethanolic extracts are the most-studied forms.

Is Black Cohosh safe? Any cautions or side effects?

Generally well tolerated; the most common effects are GI upset, headache, rash and mild weight gain. Rare but serious idiosyncratic liver injury — including cases of acute liver failure requiring transplant — has been reported, so stop and seek care for jaundice, dark urine, or right-upper-abdominal pain (NIH LiverTox likelihood score A). Avoid in pregnancy, breastfeeding, and active or hormone-sensitive cancers until cleared by a clinician; use caution alongside other hepatotoxic drugs, statins, acetaminophen or alcohol, and with antihypertensives or sedatives. Product quality varies, and some supplements have been adulterated with the wrong Actaea species.

How many studies support Black Cohosh?

NutriDex cites 7 sources for Black Cohosh, graded "Mixed".

Does Black Cohosh interact with any medications?

Yes — known or theoretical interactions include: Pregnancy (avoid), Hormone therapy / tamoxifen (caution), Liver-stressing drugs / alcohol (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Black Cohosh with any medicine.

Cite this page
APA

Peh, D. (2026). Black Cohosh (Actaea racemosa): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/black-cohosh

BibTeX
@misc{nutridex_black_cohosh,
  author       = {Peh, Daryl},
  title        = {Black Cohosh (Actaea racemosa): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/black-cohosh},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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