Science

A “randomized, double-blind, controlled, crossover study” in which “young, healthy volunteers” were randomized to drink two large cans of an energy drink or a control drink that had the sugar and the same amount of caffeine, but none of the other “proprietary blend ingredients” like taurine, carnitine, ginseng, guarana, and all the other stuff they add.

That's interesting because I always considered those extra additives pretty harmless. So it's the mixture of everything which has negative side effects?