Black cohosh: the most studied plant in the menopause aisle

If you have read anything at all about menopause supplements, you have read about black cohosh. It is the most studied botanical in the category by a wide margin, which means there is enough research to give you a real answer instead of a shrug. The answer is more interesting than either camp usually admits.

What it is

Actaea racemosa, formerly Cimicifuga racemosa, is a woodland plant native to eastern North America. The rhizome and root are used. It was in the United States Pharmacopoeia between 1830 and 1926, long before the supplement industry existed, and it has been the subject of clinical trials in Europe since the 1980s.

It is not a phytoestrogen in the way soy or red clover are. Its mechanism is still debated, with serotonergic activity among the leading explanations, which is part of why it behaves differently from isoflavone products in trials.

What the research shows

The most useful recent paper is an updated pairwise meta-analysis published in Menopause in 2023, covering 22 articles and 2,310 women. It found black cohosh extracts were associated with a statistically significant improvement in hot flushes compared with placebo, along with improvements on broader menopausal symptom scores.

The effect size was moderate rather than dramatic. That is the honest headline: measurable, real in the pooled data, and not the same order of magnitude as hormone therapy.

A separate review and meta-analysis focused on the isopropanolic extract reached similar conclusions for that specific preparation, which is the one most European trials used.

Where the evidence is thinner

Not every trial found an effect, and the ones that did not are worth knowing about. The NIH Office of Dietary Supplements fact sheet is the fairest summary of the mixed picture. The HALT trial, with 351 participants, found no improvement over placebo in perimenopausal women, and several smaller studies also came back null.

Two things explain most of that spread. Trials used different extracts prepared in different ways, and results from one preparation genuinely do not transfer to another. And the placebo response in menopause trials is enormous, frequently 30 to 50 per cent, which makes a modest real effect hard to detect without large numbers.

Doses in the trials clustered around 40 mg per day of a standardised extract, over 8 to 12 weeks.

The liver question, straight

You will find warnings about black cohosh and liver injury. Here is the state of it.

More than 50 case reports have been published linking black cohosh products to liver problems, ranging from mild hepatitis to, very rarely, liver failure. That is why the warnings exist and why they should be taken seriously.

Against that, a critical review of the causality assessments found that when the reported cases were examined individually, almost all had confounding factors: other medications, other supplements, pre-existing conditions, or products that turned out not to contain black cohosh at all. Meta-analyses of controlled trials have not shown an effect on liver function tests.

The reasonable position is not "it is dangerous" and not "the warnings are nonsense". It is: the signal is real enough to respect, the causality is unproven, and if you have liver disease, drink heavily, or take medication that affects the liver, this is a conversation with your doctor before you start rather than after.

Who should be careful

Not during pregnancy or breastfeeding. Not under 18. Speak to your doctor first if you have or have had a hormone-sensitive condition, if you are on hormone therapy or tamoxifen, or if you have liver problems. Stop and seek advice if you notice unusual fatigue, dark urine or yellowing of the skin or eyes.

What is in PEACH POWER

Two capsules a day contain Black Cohosh Root Extract, 160 mg, alongside red clover, sage, dong quai, chasteberry and six more botanicals, each with its own amount printed on the panel.

We do not hide it inside a proprietary blend, because the whole point of reading a label like this is being able to hold it against the research above. The full ingredient breakdown is here.

See PEACH POWER

Sources

• Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis. Menopause, 2023.
• Review and meta-analysis: isopropanolic black cohosh extract iCR for menopausal symptoms, an update on the evidence. Climacteric, 2021.
• Black cohosh: health professional fact sheet. NIH Office of Dietary Supplements.
• Teschke R. et al. Black cohosh and liver toxicity: is there a relationship?

This article is general information, not medical advice. 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.