Know2eat

Black cohosh

Actaea racemosa

Herbs & Botanicals

What black cohosh may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedMenopausal symptomsLimited evidence· 2 sources

Then, in order

About Black cohosh

A rhizome extract used for menopausal hot flushes, standardised to triterpene glycosides. Despite decades of use, its mechanism is unresolved and it does not appear to act as a phytoestrogen.

Black cohosh trials are numerous and inconsistent: some report reduced hot flush frequency, the larger and better-controlled ones often do not, and Cochrane reviewers concluded there is insufficient evidence to support it. Liver injury reports led regulators in Europe, Australia and elsewhere to require warning labels. Species substitution with Asian Actaea species has been documented repeatedly.

Sold as
Standardised rhizome extract tablet, Capsule, Tincture, Combination menopause formulas
Standardised to
Commonly standardised to 1–2.5% triterpene glycosides; trials often used a branded isopropanolic extract — a product without this marker may not resemble what was studied.
Also known as
Cimicifuga racemosa, Black snakeroot, Remifemin

Regulation: European, Australian and UK regulators require liver-warning statements on black cohosh products following case reports of hepatotoxicity. It remains available over the counter in most markets with that warning.

What the research used

The amounts, forms and durations published trials of Black cohosh actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Menopausal hot flushes

    20–80 mg

    Limited

    Standardised extract, once or twice daily · Trials typically used 20 mg of an isopropanolic extract twice daily · 8 weeks to 12 months

    Trials mostly used one branded European extract, many of them manufacturer-supported, and results across the wider literature do not consistently agree with them.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • With food

    Not enough

    Taken with food for tolerability. No timing comparison has been published.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Menopausal symptoms

Women's Health
Limited evidence

Some trials report reduced hot flush frequency and severity, while others find no difference from placebo, and systematic reviewers conclude the evidence is insufficient. Hot flush trials have a notably large placebo response, which makes small studies unreliable here.

Limited evidence. Early human work, or mostly lab and animal research.

View the 2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Mood

Mental Wellbeing
Not enough evidence

Evidence is limited for black cohosh and mood in menopause. Where it has been studied it was usually combined with St John’s wort, which brings its own substantial interaction risks.

Not enough evidence. Not enough human research to say anything useful yet.

View the 1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Worth knowing

    Liver injury reports

    Cases of hepatitis and liver failure, some requiring transplantation, have been reported with black cohosh. Causality is debated and species substitution may play a part, but regulators in several countries mandate a liver warning. Jaundice, dark urine or unexplained fatigue means stopping immediately.

  • Avoid

    Pregnancy and breastfeeding

    Black cohosh has traditional use to induce labour and reports of neonatal complications after use near delivery. It should not be used in pregnancy.

  • Worth knowing

    Species substitution

    DNA testing has repeatedly found Asian Actaea species substituted for Actaea racemosa in retail products. Those species have different chemistry and are suspected in some adverse reports.

  • Worth knowing

    Hormone-sensitive conditions

    Although it does not appear to be oestrogenic, safety in breast cancer, endometrial cancer and endometriosis is not established, and specialist advice is warranted before use in those situations.

  • Interaction

    Liver-affecting and chemotherapy drugs

    Interacts withHepatotoxic drugs, alcohol, cisplatin, tamoxifen

    Combining it with other hepatotoxic drugs or alcohol compounds a documented concern, and laboratory work suggests possible interference with some chemotherapy agents.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Black cohosh, or a dose to follow.