Taurine is an amino acid produced naturally in the human body that is also found in meat, seafood, and milk. Energy drinks can contain anywhere from 20 to 2,000 mg of taurine. Though there is no scientific basis to the idea that it increases mental or physical performance (“Red Bull gives you wings!”)—some research suggests that large amounts of taurine would actually have a sedative effect—energy drink companies add taurine to their products to capitalize on this common misconception.
Several years ago, France, Denmark, Norway, and Uruguay outlawed Red Bull outright because of concerns over taurine. The European countries were forced to legalize it in 2008 due to EU regulations, but French authorities remain skeptical of the ingredient and its neurophysiological effects. (Red Bull is still illegal in Uruguay.)
Notably, due to the lack of information about its long-term effects on the human body, taurine is not on the FDA’s approved list of GRAS additives.