Black cohosh (BC) (Actaea racemosa or Cimicifuga racemosa) herb is used for symptoms of menopause. It is native to North America. Discussions have been made about whether BC is toxic to liver in women who are sensitive to it. In one study, the United States Pharmacopeia (USP) said that liver toxicity was caused by BC in 30 cases.However, it has been found that those cases were not substantiated and were poorly documented. So, the claim for hepatotoxicity of BC was not well established.
We need improved techniques for evaluation of toxicity. The history must be well documented. The taking of BC must be timed relative to the onset of liver damage. The signs and symptoms of liver problems should improve when BC is discontinued. Blood tests for alanine aminotransferase (ALT) and/or alkaline phosphatase (ALP) must be appropriately elevated to confirm herb toxicity. Other possible cases of hepatotoxicity must be ruled out. (There is a long list of hepatotoxic drugs and herbs.)
The authors reviewed nine cases of suspected BC hepatotoxicity in the literature using the International Organizations of Medical Sciences scale. In eight cases, BC was excluded or believed to be highly unlikely to be the cause of the patient’s liver failure. Often, the dosage and brand of the BC was not known. In some cases it was not known whether the BC was taken as a single herb or in combination with other plants. In one case, BC of unknown brand and unknown dose taken for two months was believed to have, possibly, been the cause of liver failure. This was complicated by the presence of symptomatic gall bladder stones and fatty liver. Five of the nine patients were taking additional drugs and herbs or other nutritional supplements.
CONCLUSION: Only 11 possible cases of BC hepatotoxicity have been established, worldwide. In only one out of nine patients who developed liver failure on BC and studied by the authors was there evidence that the problem could have been caused by the BC. This study concludes there is almost no evidence that BC is hepatotoxic.
NOTE: Read about further attempts and failure to establish causality of BC in hepatotoxicity.
To read the author’s abstract of the article click on the link to the author’s title of the article above.