Black Cohosh Side Effects

Black cohosh (Actaea racemosa) goes by many names, including bugwort and black snakeroot, and has been used for hundreds of years as a Native American herbal treatment for various disorders, reports the National Center for Complementary and Alternative Medicine. Though it may have several health benefits, black cohosh supplements may also cause severe side effects. Talk to your doctor before incorporating it into your supplementation regimen.

Female Health Problems

A 2002 study, published in the "Journal of the American Medical Association," found a significant increase in the risk of various diseases, including cancer, that may affect breast or uterine tissue in postmenopausal women. This may be due to the herb's effects on estrogen levels.

Allergies

Avoid black cohosh supplements if you're allergic to Ranunculaceae plants, such as buttercups, or aspirin, warns the Mayo Clinic. Adverse allergic effects vary by individual, but may include rashes or trouble breathing.

Liver Problems

Black cohosh may cause liver health problems and even liver failure. The National Institutes of Health's Office of Dietary Supplements advises against taking this herb if you have a liver disease or disorder, and to stop taking it if you experience signs of liver distress such as jaundice, abdominal pain and dark-colored urine. The office reports that there have been cases of people requiring liver transplants after taking black cohosh.

Gastrointestinal Effects

The University of Maryland Medical Center warns that black cohosh supplements may cause problems related to the digestive tract, including diarrhea, weight gain, cramps and vomiting.