I gotta apologize if this has been mentioned earlier but I have not read all the input on this subject, but here are the product ingredients according to Waikiperia:
The packaging usually contains a warning label advising consumers against drinking more than 48 oz per day (16 oz per day in Australia). The UK and Europe do not have these warning labels. The drinks are not recommended for pregnant women or people sensitive to caffeine.
The ingredients include carbonated water, sucrose, glucose, citric acid, natural flavors, taurine, sodium citrate, color added, panax ginseng root extract, L-carnitine, caffeine, sorbic acid, benzoic acid, niacinamide, sodium chloride, glucuronolactone, inositol, guarana seed extract, pyridoxine hydrochloride, sucralose, riboflavin, maltodextrin, and cyanocobalamin.
Thanks to Wikipedia for this info.