Quench your thirst without worrying about the sugar with the help of Red Bull Sugarfree! The popular energy drink also comes in a sugar-free variant loaded with the same punchiness as the classic Red Bull! So next time, whenever you trigger a headache, head to your refrigerator and sip a can of Red Bull Sugarfree. This drink carries a unique blend of high-quality ingredients, including caffeine, taurine, Alpine water and B-group vitamins. The sugar is replaced with Aspartame and Acesulfame K that are popular sugar substitutes used in drinks and similar products. All ingredients are FDA approved. An 8.4 FL OZ can of this energy drink has 80mg of caffeine, and 12 FL OZ can have 114 mg of caffeine.