Health Canada advises against use of Symphytum spp.-containing products

Health Canada is advising Canadian consumers not to use or to ingest the herb Symphytum (comfrey) or any health products that contain Symphytum because they might contain a compound called echimidine, which may cause liver damage. As a precaution, consumers are advised not to topically apply Symphytum-containing products to broken skin. There are several different species of Symphytum, two of which are already prohibited from being used in therapeutic products in Canada because they contain echimidine. These species are Symphytum asperum (prickly comfrey) and S. × uplandicum (Russian comfrey). While not all Symphytum products contain echimidine, some do not identify the species of Symphytum in the product, therefore consumers are advised to avoid all products containing Symphytum.

http://www.hc-sc.gc.ca, 12 December 2003