USA Today reports that the compound is similar to methamphetamine and "appears to have its origins as an illicit designer recreational drug." Whoa. Tests performed by Pieter Cohen, an assistant professor at Harvard Medical School, as well as others tested on samples of Craze revealed a compound — N, alpha-diethylphenylethylamine — that is similar in both composition and effect to meth. While its effects are likely less extreme (if it were actually like meth, there probably wouldn't be any Craze left on the shelves), it still hasn't been tested in the human body. And, anything that increases your blood pressure or heart rate significantly while you're working out can be dangerous.
Craze is marketed as providing "unrelenting energy and focus" in workouts. Yep — we hear meth does have that effect. (USA Today)