What the research says about black cohosh for hot flashes and night sweats, why its liver warning matters, and how it compares with options menopause experts recommend.
Black cohosh may help menopause symptoms a little, but the evidence is mixed: several rigorous trials found it no better than placebo, and The Menopause Society does not recommend herbal remedies for hot flashes. It's usually well tolerated, but it has been linked to rare, sometimes severe liver injury. Avoid it if you have liver disease, are pregnant or breastfeeding, or have a hormone-sensitive cancer history without your doctor's input.
Black cohosh (Actaea racemosa, formerly Cimicifuga racemosa) is a North American plant in the buttercup family. Supplements use its root and rhizome, and it's one of the most widely sold herbs for menopause symptoms, especially hot flashes and night sweats. It's sold alone, as standardized extracts such as Remifemin, and as one ingredient in multi-herb women's formulas.
Don't confuse it with blue cohosh, a different plant. NCCIH warns that blue cohosh may cause high blood pressure, high blood sugar and chest pain, and that using it to induce labor has been linked to life-threatening complications in newborns.
This is a herb where good-quality trials disagree. Some reviews find a modest benefit; several of the best-designed individual trials found none.
| Study or review | What it found |
|---|---|
| Newton et al. (2006), 351 women, 12 months, 160 mg/day | No difference from placebo in hot flash or night sweat frequency or intensity |
| Geller et al. (2009), 88 women, 12 months, 128 mg/day | Symptoms fell in all groups, but black cohosh did no better than placebo |
| Cochrane review (2012), 16 trials, 2,027 women | Insufficient evidence to support or oppose its use for menopausal symptoms |
| Franco et al. (2016), 4 trials, 511 women | No significant reduction in vasomotor symptoms |
| Review cited by NCCIH (2023), 22 studies | Potentially beneficial for overall menopause symptoms, including hot flashes, but not anxiety or low mood |
Those trial details come from the NIH Office of Dietary Supplements fact sheet, which also notes that doses in trials ranged from 8 to 160 mg a day, with a median of 40 mg. Products vary a lot in extract type and strength, which is one reason results are hard to compare.
It's also uncertain whether black cohosh helps hot flashes caused by breast cancer treatment, a group where it's often marketed.
The Menopause Society (formerly the North American Menopause Society) is not convinced. Its 2023 position statement on nonhormone therapies recommended cognitive behavioral therapy, clinical hypnosis, SSRI and SNRI antidepressants, gabapentin and fezolinetant, a newer FDA-approved drug, for hot flashes. It did not recommend supplements and herbal remedies. The ODS fact sheet notes the society has described black cohosh as unlikely to be beneficial for vasomotor symptoms.
Hormone therapy is another option for many women, and a doctor can help you weigh its benefits and risks against the nonhormone choices above, based on your age, health history and how much the symptoms affect you. That conversation is worth having before spending months on an herb with uncertain benefit. If you're looking at supplements more broadly for this stage of life, our guide to the best supplements for women over 50 covers what's worth considering.
Black cohosh is generally well tolerated in studies lasting up to a year. The most commonly reported side effects are mild, short-lived stomach upset and rashes.
The serious concern is liver injury. The NIH's LiverTox database describes more than fifty cases of clinically apparent liver injury linked to products labeled as black cohosh. Most showed up within 2 to 12 weeks of starting, and severity ranged from abnormal blood tests to acute liver failure requiring a transplant, including deaths. LiverTox rates black cohosh products as a well-established cause of liver injury, while saying the responsible ingredient is unclear.
That uncertainty matters. Some implicated products turned out to contain Asian Actaea species instead of true black cohosh, and NCCIH says contamination or mislabeling might explain some cases, though that hasn't been proven. The ODS fact sheet notes there's no proven causal link. Either way, the risk is real enough that the US Pharmacopeia recommends black cohosh labels tell people to stop use and consult a healthcare practitioner if they have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine or jaundice. The FDA doesn't require that warning, so many labels don't carry it.
Stop taking it and contact a doctor promptly if any of these appear.
Black cohosh is also sometimes combined with other herbs that carry their own cautions, such as phytoestrogens like red clover or soy isoflavones, or ginkgo, which may raise bleeding risk with blood thinners like warfarin. If you take a multi-herb product, check every ingredient.
Black cohosh also turns up in some women's libido formulas. Provestra, for example, lists it among 21 ingredients without stating the dose. We cover how much that formula has to offer in does Provestra work, and its liver and hormone cautions in our article on Provestra side effects. The same liver symptoms apply whether black cohosh comes alone or in a blend.
Black cohosh is one of the most studied herbs for menopause, but the results are mixed: some reviews suggest a modest benefit, while several well-run trials found it no better than placebo, and The Menopause Society doesn't recommend herbal remedies for hot flashes. It's usually well tolerated, yet it's tied to rare, sometimes severe liver injury. If hot flashes are affecting your sleep or daily life, talk to your doctor about proven options first. If you still want to try black cohosh, avoid it with liver disease, pregnancy, breastfeeding or a hormone-sensitive cancer history, and know the warning signs.