C4 Ultimate X WWE Energy Drink Highlights: Fuel Ultimate Undisputed Performance with C4 Ultimate Energy™! Supercharged with 300mg of caffeine, you can go from working hard to playing hard without missing a beat. C4 Ultimate Energy™ is formulated with clinically studied BrainBerry® and Cognizin® Citicoline for SuperBrain Performance™. SUPERCHARGED ENERGY When you need to go hard, supercharge with C4 Ultimate Energy™. Every can is packed with 300mg of hard-hitting caffeineEvery can of C4® Ultimate Carbonated is loaded with incredible flavors and the perfect amount of carbonation to kick-start your taste buds. SUPERBRAIN PERFORMANCE™ C4 Ultimate Energy™ is formulated with clinically studied BrainBerry® and Cognizin® Citicoline to support cognitive function and elevate your focus to the ultimate level.