title: Toxicity of comfrey-pepsin preparations.
mesh_terms: D000481:Allantoin / Q000633:toxicity*; D005765:Gastrointestinal Agents / Q000633:toxicity*; D006801:Humans; D011763:Pyrrolizidine Alkaloids / Q000633:toxicity*
chemical_list: D005765:Gastrointestinal Agents; D011763:Pyrrolizidine Alkaloids; D000481:Allantoin