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.
Outcome
Evidence
Effect
Studies
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.
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
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 8 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 16 Sept 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 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.