There was an interesting article about the Red Bull founder in a recent special issue of the Sunday New York Times Sunday Magazine.
Partially from from Snopes:
"Red Bull . . . does contain glucuronolactone. But as we've seen, that ingredient is apparently innocuous.
. . . The caffeine in one can of Red Bull (80 mg) equals that of one cup of black coffee (which varies in caffeine content from 80 to 180 mg depending on how it is prepared). The drink also contains taurine, a derivative of the sulfur-containing amino acid, cysteine. . . . "