COMFREY is a member of the Borage family (Boraginaceae). This herb is known to hinder the blood supply to the liver. AVOID with liver cysts. Contains pyrrolizidine alkaloids which have hepatotoxic and carcinogenic effects (may be toxic to the liver and cause cancer when taken internally. The topical application of comfrey-containing preparations to broken skin should be avoided. This is to be used externally only. If ingested it can be harmful to the liver.