Actaea racemosa L. (syn. Cimicifuga racemosa) · herb
Evidence tier: limited
Reduces hot flushes, night sweats, and mood disturbances in menopause, one of the most studied herbs for menopausal symptom relief
Not what people assume. Black cohosh is NOT an estrogen and does not behave like one: MSK reports it 'has no effect on LH, FSH, prolactin, or estradiol levels'. The current view is that it acts on the brain rather than on hormone receptors, through dopaminergic, noradrenergic, serotoninergic and GABAergic pathways, which is thought to reset the hypothalamic thermostat that fires a hot flush. This is the leading explanation, not a proven mechanism. Separately, the mechanism of the liver injury is unknown: LiverTox states black cohosh 'does not appear to be inherently hepatotoxic', that the reaction looks idiosyncratic and possibly immune mediated, and that the specific responsible component has never been identified. Nobody can predict who it will happen to.
READ THE SAFETY PARAGRAPH FIRST. NIH LiverTox assigns black cohosh a hepatotoxicity likelihood score of A, the TOP of its scale, defined as 'products sold as black cohosh are well established causes of clinically apparent liver injury.' Over 50 cases are on record, ranging from silent enzyme elevations to jaundice, autoimmune like hepatitis, massive hepatic necrosis, EMERGENCY LIVER TRANSPLANTATION and DEATH. Latency runs from 1 to 48 weeks and typically lands at 2 to 12 weeks, which is exactly the window in which a woman would still be waiting to see if it works. This is not a theoretical signal: it is regulated. Australia's TGA mandates the label warning 'Black cohosh may harm the liver in some individuals. Use under the supervision of a healthcare professional.' The UK MHRA required liver warnings on all black cohosh products. The EMA HMPC reviewed 42 European case reports and requires that patients STOP the product immediately and see a doctor at the first sign of tiredness, loss of appetite, yellowing of the skin or eyes, dark urine or severe upper abdominal pain with nausea and vomiting. NCCIH: 'cases of liver damage, some very serious, have been reported in people taking products labeled as black cohosh.' Now the efficacy, which is genuinely mixed and must not be inflated to justify that risk. The Cochrane review (Leach and Moore 2012, 16 trials, 2,027 women), the only synthesis with formal risk of bias assessment, found INSUFFICIENT EVIDENCE and reported 'no significant difference between black cohosh and placebo in the frequency of hot flushes or in menopausal symptom scores'. Against that, a 2023 updated pairwise meta analysis in Menopause (PMID 37192826, 22 articles, 2,310 women) DID find a statistically significant benefit for overall menopausal symptoms and for hot flashes, though the hot flash effect size was small (Hedges g 0.315) and there was no benefit at all for anxiety or depression. NCCIH splits the difference: 'data on specific symptoms showed improvements in hot flashes but not anxiety or depressive symptoms.' The EMA is the strongest card in black cohosh's hand and it is a real one: unlike most herbs, black cohosh holds WELL ESTABLISHED USE status for hot flushes and excessive sweating in menopause, and EMA caps it at 6 months without medical review. Honest verdict: LIMITED. Small, inconsistent effect on hot flushes only, contradicted by the highest quality synthesis, sitting on top of a LiverTox score A. PlantRx correctly flags this ingredient as Brain only and requiring Remy screening, and that flag should never be relaxed.
Trials cluster on 40 mg of extract daily, with the studied range running from 8 to 160 mg per day and a median of 40 mg. The most studied preparation by far is the isopropanolic extract (the product Remifemin), standardised to the equivalent of 40 mg of root and rhizome per daily dose. Products are frequently standardised to at least 1 mg of triterpene glycosides per daily dose. EMA hard limit: adult women only, and NOT longer than 6 months without consulting a doctor.
Take 20 to 40mg of standardised extract (standardised to triterpene glycosides) twice daily. Allow 8 to 12 weeks to assess full benefit. Evidence is specifically for hot flush frequency and severity.
Avoid in pregnancy, may stimulate uterine contractions. Avoid in breastfeeding due to insufficient safety data. Rare cases of hepatotoxicity reported; monitor liver function with long term use. Contraindicated in hormone sensitive conditions (breast cancer history).
Pregnancy: avoid
Breastfeeding: avoid
Active compounds: triterpene glycosides, actein, 23-epi-26-deoxyactein, cimicifugoside, polyphenols
Remedies using Black Cohosh · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.