The Federal Drug Administration has said that all products containing the additive must be taken off the market immediately.美国食品和药物管理局说，凡是含这种添加剂的产品都必须立即撤出市场。The drug has been approved by the U.S. Food and Drug Administration.这种药物获得了美国食品和药物管理局的批准。The FDA has granted researchers permission to use the drug experimentally on humans.美国食品和药物管理局允许研究人员在人身上试用这种药物。