Black/Blue CohoshLiver Disease

Differing point of view on black cohosh and liver toxicity

Drs. Luigi Gori and Fabio Firenzuoli from the Center of Natural Medicine, S. Giuseppe Hospital in Italy think the European Medicines Agency (EMEA) and the Committee on Herbal Medicinal Products (HMPC) erred in their assessment of the risk of liver toxicity to Cimicifugae racemosae rhizoma (black cohosh, root).

The EMEA and HMPC reviewed 42 reports and reported that the cases were “poorly documented,” and only “two can be considered as possible” and “two can be classified as probable.”

They concluded, “The HMPC would like to draw the attention of the public to the potential serious hepatic reactions that may occur in patients using herbal medicinal products containing Cimicifugae racemosae rhizoma (black cohosh, root).

Not so fast say Gori and Firenzuoli.
“In our opinion it is very important to know the brand, the dose of substance consumed, the type of extract, the content of possible contaminants (wrong plants, pesticides, heavy metals, aflatoxins) before making an official statement about any adverse reaction to a herb-based product.”

If the preparation investigated contains several substances, no clear connection can be established between adverse reactions and a single herb, unless it is a well-known hepatotoxic substance or it accounts for a very high proportion in the respective remedy.

They believe, “For the time being, the EMEA statement can, paradoxically, be regarded as the proof that the risk of black cohosh hepatoxicity is small: although every year millions of doses of black cohosh are used worldwide?, no fully documented case of liver adverse reaction has been reported so far. To the contrary, safety of black cohosh can be regarded as sufficiently established by the fact that clinical trials in a total of more than 2,000 participants have not reported any hepatotoxic reactions.

Hat tip to Jonathan Treasure’s Herblog.

8/11/07 21:27 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.