A Harvard medial study is warning about a pre-workout supplement with a chemical in it that's similar to meth. The study focuses on supplement called Craze made by the company Driven Sports. The product is marketed to bodybuilders. The study's lead author says the supplement meth like substance has never been studied in humans. Driven Sports say independent lab testing showed Craze contains no illegal stimulants. The study is published in the journal "Drug Testing and Analysis . "