Powered by InnovaTea® Naturally Derived Caffeine (from Tea), brain-boosting Cognizin® Citicoline, and the additional support of N-Acetyl L-Tyrosine, C4 Smart Energy delivers energy, focus, and mental performance to help you conquer any task—from work to play, gaming to studying, partying to planning. C4 Smart Energy is proudly made with natural flavors, no artificial colors or dyes, and contains zero calories, sugar, or carbs.