Black Cohosh for Hot Flashes: Evidence, Liver Warnings and Label Checks

Black cohosh is a North American plant in the buttercup family. Supplements made from its root are sold widely for hot flashes and night sweats.¹ If you’d rather not take hormones, it’s an easy bottle to pick up. Here is what the evidence and safety record show.

Does it help hot flashes?

A 2023 review pooled 22 studies with 2,310 women. Black cohosh products, alone or combined with other herbs, were linked to improvements in overall menopause symptoms and hot flashes compared with placebo. They didn’t significantly improve anxiety or depression.¹² Dropout rates were similar to placebo.²

It’s uncertain whether black cohosh helps hot flashes caused by breast cancer treatment.¹ Many of the studies used different extracts, doses and combinations, so results may not apply to the product on your shelf.

The liver question

Black cohosh has been used in studies lasting up to a year and is generally well tolerated. But cases of liver damage, some very serious, have been reported in people taking products labeled as black cohosh.¹ These cases are rare, and it’s uncertain whether black cohosh itself was to blame.¹

One concern is quality. Some products have been found to contain the wrong herb or unlisted herbal mixtures.¹ Black cohosh contains more than 100 chemical compounds, and commercial products can differ widely in what’s in them.³ Supplements don’t need FDA approval before they’re sold.¹

Watch for signs of liver trouble, such as dark urine and tiredness, and contact your clinician if they appear.¹

Other cautions

• Black cohosh isn’t blue cohosh, a different herb with its own risks.¹
• After breast or uterine cancer, it’s uncertain whether black cohosh is safe.¹
• Medicines: some herbs interact with medicines, so check with your clinician or pharmacist first.¹

Label checks

1. Look for one herb, not a long blend, so you know what you’re taking. Our guide to menopause supplement blends explains how to read them.
2. Check that the plant part is root or rhizome.¹
3. Look for third-party quality testing on the label.
4. Track your hot flashes for a few weeks before and after starting.
5. Tell every clinician you see that you take it.

Our article on hot flash help without hormones compares options with stronger evidence, including prescription medicines.

Try: “I’ve been taking black cohosh for hot flashes. Is it safe with my other medicines and liver health, and are there better-tested options for me?”

My Body Changed. Now What? includes a Visit Brief. Use it to list your symptoms, supplements and medicines so your clinician can review them together. See the book.