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Dietary Supplement Black Cohosh Linked to Liver Toxicity

Worst Pills, Best Pills Newsletter article August, 2006

The Australian equivalent of the Food and Drug Administration (FDA) reported in the April 2006 issue of the Australian Adverse Drug Reactions Bulletin that 49 cases of liver toxicity worldwide have been associated with the use of the dietary supplement black cohosh.  

Of the 49 suspected cases of liver toxicity known to the Australian regulators, patients experienced liver failure that required a liver transplant in four cases. Serious cases of liver toxicity have occurred with the use...

The Australian equivalent of the Food and Drug Administration (FDA) reported in the April 2006 issue of the Australian Adverse Drug Reactions Bulletin that 49 cases of liver toxicity worldwide have been associated with the use of the dietary supplement black cohosh.  

Of the 49 suspected cases of liver toxicity known to the Australian regulators, patients experienced liver failure that required a liver transplant in four cases. Serious cases of liver toxicity have occurred with the use of black cohosh for less than a month.

Black cohosh is a plant widely sold in health food stores and on the Internet to treat hot flashes and other menopausal symptoms. The plant goes by a number of common names, including black snakeroot, bugbane, bugwort, rattleroot, rattletop, rattleweed and macrotys. Insects avoid it, which accounts for some of these names. Smart bugs!

Dietary supplements such as black cohosh are, for all practical purposes, unregulated in the United States. These products can legally be sold in this country without any evidence that they will do what their producers say they will do and without evidence that they are safe.  

A backward law passed in 1994, called the Dietary Supplement Health and Education Act (DSHEA), opened the door for the dietary supplement industry and the American public has to relive the risks of an unsafe drug marketplace that existed before the passage of the Federal Food and Drugs Act in 1906.    

Black cohosh was listed as a Do Not Use product in the 2005 edition of Worst Pills, Best Pills because there is no evidence that it is effective.

If you develop any of the symptoms of potential liver toxicity while taking black cohosh, seek medical attention immediately. These symptoms are:

  • Pruritus (itchy skin)
  • Jaundice (yellowing of the skin or whites of the eyes)
  • Dark urine
  • Upper right-sided abdominal tenderness (locaton of the liver)
  • Unexplained “flu-like” symptoms

What You Can Do

You should not use products containing black cohosh. There is no reliable evidence of a benefit and growing evidence of harm with this dietary supplement.