Hepatotoxicity of Botanicals

The scale of the problem of hepatotoxicity of botanicals is reviewed. This problem was found to be very small, largely limited to idiosyncratic reactions (as opposed to intrinsic toxicity of herbal compounds for the liver), and hampered by the availability of high-quality evidence against intrinsic hepatotoxicity. Claims that herbal hepatotoxicity is common but hidden could not be substantiated. Various herbs sometimes considered hepatotoxic are reviewed in depth, including Piper methysticum (kava); Larrea tridentata (creosote bush); unsaturated pyrrolizidine alkaloid–containing herbs, such as Symphytum officinale (comfrey) and Tussilago farfara (coltsfoot); Cimicifuga racemosa (black cohosh); and Camellia sinensis (green tea) and its catechins.