Side Effects And Interactions Of Black Cohosh

Black cohosh is a large flowering plant native to North America commonly used by Native Americans for its medicinal properties. Today it is available as a dietary supplement in the United States and other countries to help relieve symptoms of menopause such as menstrual cramps and hot flashes. Researchers are not certain of black cohosh's health benefits; rarely, it may cause serious side effects in some people.

Side Effects

A variety of side effects can occur while taking black cohosh. Gastrointestinal side effects may include abdominal pain, nausea and diarrhea, vomiting and constipation. Other reported side effects include headache and dizziness, tremors, slow heart rate, weight gain and visual disturbances. The bones and joints may be negatively affected, resulting in joint pain and low bone mass, which increases the risk of osteoporosis, according to MayoClinic.com.

Liver

Black cohosh may lead to possible liver damage, or hepatitis and liver failure, although direct associations have yet to be established. People with liver damage or who drink large amounts of alcohol should not take black cohosh. Dr. Stanley Cohen from Rush University Medical Center reports a variety of ways in which black cohosh may damage the liver. These include direct toxicity to liver cells or toxicity from black cohosh byproducts, allergic reactions and overuse of black cohosh, as reported at the 2004 Workshop on the Safety of Black Cohosh in Clinical Studies, organized by the National Center for Complementary and Alternative Medicine and Office of Dietary Supplements.

Interactions

Herbs such as black cohosh should be taken only under the supervision of a health care provider to avoid interactions with other herbs, dietary supplements and medications. Black cohosh may interact or interfere with the breast cancer treatment drug tamoxifen and other chemotherapy drugs such as doxorubicin and docetaxel, according to the Memorial Sloan-Kettering Cancer Center.

Allergic Reaction

People allergic to black cohosh or plants in the buttercup or crowfeet family should not use black cohosh. People who are allergic to aspirin or salicylic acid should also not use black cohosh to avoid potentially severe allergic reactions, according to MayoClinic.com. Seek medical attention if signs of an allergic reaction are present, including include rash, hives or itching of the skin, swelling of the face, throat or tongue, breathing difficulties or watery, red eyes.