SASSAFRAS (SARSAPARILLA) FDA has banned safrole contained in both sassafras & sarsaparilla. This is the oil from sassafras root; those who took large doses of safrole developed permanent liver damage or various types of cancer. In humans, liver damage can take years to develop and it may not have obvious signs. Along with commercially available sarsaparilla, sassafras remains an ingredient in use among hobby or microbrew enthusiasts. It is a known carcinogen.