FDA said it is toxic because when they gave 56,000Xtheir weight in it to rats over a whole 2 years ONE out of 28 rats got a liver tumor. all the rats in the comfrey group developed a type of tumor known as adenoma, which is a benign growth(all rats get them after 2 years anyway. our pet ones did) that's all the testing that was done 50 years ago. because pharma cant make a dime off comfrey
