4F-MPH is a novel psychoactive substance that is a fluorinated analogue of the prescription central nervous system stimulant methylphenidate (MPH), a dopamine and norepinephrine reuptake inhibitor used to treat attention deficit hyperactivity disorder. (±)-threo- and (±)-erythro- diastereomers (±) are present in 4F-MPH powders, but the bioactive compounds are (±)-threo-4-fluoromethylphenidate (4F-MPH). At present, studies have shown that 4F-MPH is toxic and has certain effects on the mind and heart of the human body[1].