Black Cohosh

Reviewed by Melinda Ratini, DO, MS on January 19, 2021

For centuries, the roots of the North American black cohosh plant have been used for various ailments. Black cohosh is now a popular remedy for the symptoms of menopause. This has been especially true since the risks of a standard treatment for menopause -- hormone therapy -- were publicized more than a decade ago.

Why do people take black cohosh?

Black cohosh is most often used to control the symptoms of menopause, such as:

Some studies have found evidence that black cohosh does help with these symptoms. However, many experts consider the evidence unclear and say that we need more research.

Other uses of black cohosh have less scientific support. Women sometimes take it to regulate periods, ease PMS symptoms, and induce labor. Black cohosh has also been used to relieve arthritis pain and help lower blood pressure. Definitive research has not verified black cohosh's effectiveness for these uses.

How much black cohosh should you take?

For menopausal symptoms, the dose of black cohosh used in some studies has been 20-40 milligram tablets of a standardized extract taken twice a day. Directions for taking black cohosh in other forms will vary. Some experts say that no one should take black cohosh for more than six months at a time.

Can you get black cohosh naturally from foods?

No. There are no food sources for black cohosh.

What are the risks of taking black cohosh?

  • Side effects from black cohosh include headaches and upset stomach, but there are many others. Side effects may be more likely to occur at high doses. There have been some people who may have developed liver problems after using black cohosh, the specifics of which are still being investigated. Nonetheless, people with pre-existing liver problems, or those taking any other medication/substance that affects the liver, should either avoid black cohosh or check in with their health care provider prior to use.
  • Risks. Black cohosh may not be safe for:
    • Women who are pregnant (although it is sometimes used to induce labor)
    • Women who have -- or have had -- breast cancer or uterine cancer
    • Women who have endometriosis
    • Children under 18
    • People with liver disease, a high risk of stroke or blood clots, or seizure disorders
    • People with allergies to aspirin
  • Interactions. People taking other medicines including birth control pills, hormone replacement therapy, sedatives, or blood pressure medicine should not take black cohosh without the approval of their doctors.

Show Sources

Longe, J., ed. The Gale Encyclopedia of Alternative Medicine, second edition, 2004.
Natural Standard Patient Monograph: "Black Cohosh."
National Center for Complementary and Alternative Medicine: "Herbs at a Glance: Black Cohosh."

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