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Supplement

Black Cohosh (Cimicifuga)

Herbs · Cimicifuga racemosa, Actaea racemosa, black cohosh, Traubensilberkerze, Cimicifugae rhizoma

In Germany, black cohosh is an approved herbal medicine for hot flushes and sweating during the menopause. Whether it does more than placebo is answered differently by the major reviews: a 2023 meta-analysis finds a moderate effect, the 2012 Cochrane review no difference. Medicines carry a liver warning, and the authorities do not recommend the plant for use in foods.

What black cohosh is

Black cohosh, botanically Cimicifuga racemosa or, today, Actaea racemosa, is a perennial from North America. The dried rootstock is used, usually as a dry extract made with ethanol or isopropanol. In its EU monograph revised in 2018, the European Medicines Agency (EMA) describes three such extracts as medicines with well-established medicinal use for hot flushes and excessive sweating during the menopause.

In the BK-Score, human evidence stands at 7 out of 10 points. This axis rates the state of knowledge, not the substance: well studied does not mean clearly effective here, because the reviews reach opposite conclusions. Mechanism stays at 3 out of 10, because nobody can say exactly how the plant works.

How it works

A mode of action has not been established. The review on the isopropanol extract reports that hormone levels remained unchanged in the studies and that estrogen-sensitive tissue such as the breast and the uterine lining was not affected. An estrogen-like action therefore does not explain a possible effect. The German federal and state plant list names tetracyclic triterpene glycosides as critical constituents.

In practice, this means: the results apply to the extracts tested. A powder or an extract made differently is not automatically the same.

What is well supported

  • Officially recognized as a medicine. The EMA classifies three defined extracts as well-established medicinal use for hot flushes and excessive sweating during the menopause, not merely as traditional use.
  • A moderate effect in the latest meta-analysis. Across 22 papers with 2,310 women, menopausal complaints overall improved compared with placebo with Hedges’ g = 0.575 (0.283 to 0.867), hot flushes with g = 0.315 (0.107 to 0.524).
  • Tolerability at placebo level. In the same analysis, no more women dropped out under black cohosh than under placebo (odds ratio 0.911).
  • Liver values unremarkable in studies. In 5 randomized trials with 1,117 women, liver values did not change under the isopropanol extract over 3 to 6 months. The analysis comes from the manufacturer’s circle.

What the studies show

Cochrane 2012: no difference from placebo

Leach and Moore analyzed 16 randomized trials with 2,027 peri- and postmenopausal women. The mean daily dose was 40 mg, and treatment lasted 23 weeks on average. For the number of hot flushes there was no significant difference from placebo (0.07 hot flushes per day; −0.43 to 0.56; 3 trials, 393 women), nor for the symptom scores (SMD −0.10; −0.32 to 0.11; 4 trials, 357 women). Hormone therapy lowered the symptom scores more than black cohosh.

Meta-analysis 2023: moderate effect on overall complaints

Sadahiro and colleagues pooled 22 papers with 2,310 women, black cohosh alone or combined with other active ingredients. Compared with placebo, overall complaints (g = 0.575), hot flushes (g = 0.315) and physical complaints (g = 0.418) improved. Anxiety (g = 0.194) and depressive symptoms (g = 0.406) did not improve significantly. Because combination products were also included, the effect cannot be attributed entirely to black cohosh alone.

Isopropanol extract: favorable data from the manufacturer’s circle

Castelo-Branco and colleagues compiled 35 studies on the isopropanol extract iCR. Compared with placebo, there was a standardized mean difference of −0.694 for vasomotor and psychological menopausal complaints; according to the authors, the effect was comparable to low-dose transdermal estradiol or tibolone. Several authors work for the manufacturer of this extract.

Liver values: analysis of 5 trials

Naser and colleagues analyzed the liver enzymes AST, ALT and GGT from 5 double-blind controlled trials with 1,117 women aged 40 to 60, treated over 3 to 6 months. No difference was found between extract and comparison. However, rare, severe liver damage can neither be demonstrated nor ruled out with studies of this size.

Where the data stop

  • A clear benefit over placebo. The Cochrane review and newer meta-analyses contradict each other. The differences lie, among other things, in the included studies, combination products and extracts.
  • Mood and anxiety. Here, even the favorable 2023 meta-analysis found no significant effect.
  • Equivalence with hormone therapy. In the Cochrane review, hormone therapy was more effective. Anyone weighing the two can find the evidence on hormone therapy in the menopause on a separate page.
  • Rare liver damage. The EMA lists liver damage as a side effect of unknown frequency. Controlled trials are too small to capture such rare events.
  • Dietary supplements. The studies were run with defined medicinal extracts. There are no separate data on products manufactured differently.

Status, approval and legal

In Germany, black cohosh is a medicine. The EMA’s 2018 EU monograph recognizes three extracts as well-established medicinal use; in 2024 a renewed review was carried out with a call for submission of new data. On the risk of liver toxicity, the German federal and state plant list refers to an opinion of the HMPC and a decision of the Federal Institute for Drugs and Medical Devices (BfArM) on medicines containing Cimicifuga.

For foods, the situation is different. The plant list of the Federal Office of Consumer Protection and Food Safety (BVL) lists the rootstock as a medicinal substance and in list A: use in foods is not recommended because of known risks, regardless of the dosage. In the authorities’ assessment, dietary supplements with black cohosh are therefore not suitable in Germany.

Safety

The EU monograph lists liver damage, including hepatitis, jaundice and abnormal liver values, with unknown frequency. Anyone who notices fatigue, loss of appetite, yellowing of the skin or eyes, severe upper abdominal pain with nausea and vomiting, or dark urine should stop the product and have it checked by a physician immediately. Caution is advised in people with previous liver disease. Allergic skin reactions, swelling of the face and legs, and gastrointestinal complaints have also been described.

Without medical advice, black cohosh should not be taken together with estrogens or for longer than six months. Anyone who is being or has been treated for breast cancer or another hormone-dependent tumor should only use it after consulting a physician. Vaginal bleeding should be checked by a physician. It is not recommended during pregnancy and breastfeeding. In the BK-Score, safety stands at 7 out of 10 points; this axis measures how well safety has been studied, not how safe the plant is. This text is information and does not replace medical advice.

BK-Score Supported, with caveats

Human evidence7
Mechanism3
Safety data7
Hype gap5
Track record of use8

Evidence 7, because there are many randomized trials, but their syntheses contradict each other: the Cochrane review with 16 trials and 2,027 women found no significant difference from placebo for hot flushes and symptom scores (Leach 2012), whereas a newer meta-analysis of 22 papers with 2,310 women found a moderate effect on overall complaints (g 0.575) and a small one on hot flushes (g 0.315) (Sadahiro 2023); the most favorable analysis of the isopropanol extract comes partly from the manufacturer’s circle (Castelo-Branco 2021). Mechanism 3, because the mode of action has not been established; according to the review of the isopropanol extract, hormone levels and estrogen-sensitive tissue remained unchanged (Castelo-Branco 2021), so an estrogenic action does not hold as an explanation. Safety 7, because controlled data over an average of 23 weeks (Leach 2012), an analysis of liver values from 5 trials with 1,117 women (Naser 2011) and an EU monograph with pharmacovigilance are available; liver damage is listed there as a side effect of unknown frequency. Hype 5, because the advertising as a natural alternative to hormone therapy goes beyond the data, but the effect on hot flushes is not made up. Use 8, because extracts have been used for decades as approved medicines under supervision (EU monograph with well-established medicinal use). Direction mixed: positive newer meta-analyses stand against a Cochrane review with no difference from placebo.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless. “Track record of use 9” means used long and widely – that is not proof of efficacy.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about black cohosh (Cimicifuga)

Does black cohosh help with hot flushes?

The data contradict each other. A 2023 meta-analysis of 22 papers with 2,310 women found a small effect on hot flushes and a moderate one on menopausal complaints overall. The 2012 Cochrane review with 16 trials found no difference from placebo in the number of hot flushes. The EMA recognizes certain extracts as medicines for hot flushes and sweating.

Is black cohosh harmful to the liver?

The EU monograph lists liver damage such as hepatitis and jaundice as a side effect of unknown frequency. In studies with 1,117 women, liver values did not change over 3 to 6 months, but rare cases cannot be ruled out this way. In case of yellowing, dark urine, severe fatigue or upper abdominal pain, the product should be stopped and checked by a physician.

Does black cohosh act like an estrogen?

According to the available data, no. In the studies on the isopropanol extract, hormone levels remained unchanged, and the breast and uterine lining were not affected. How the plant works has not been established. According to the EMA, it should only be used together with estrogens on medical advice.

Can black cohosh be taken after breast cancer?

The EMA states that women who are being or have been treated for breast cancer or another hormone-dependent tumor should only use black cohosh after consulting a physician. The decision therefore belongs with the treating physician, not in self-medication.

Is black cohosh available as a dietary supplement?

In Germany, the authorities do not recommend this. The federal and state plant list lists the rootstock as a medicinal substance in list A, that is, as a plant whose use in foods is not recommended because of known risks, regardless of the dosage. It is available as a herbal medicine with a package leaflet and warnings.

Is black cohosh an alternative to hormone therapy?

In the Cochrane review, hormone therapy was more effective than black cohosh. For women who cannot or do not want to take hormones, it is an approved medicine with an uncertain effect. Which option fits depends on symptoms and pre-existing conditions and should be discussed with a physician.

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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-05.