C4 Energy Drink now available in a delicious and sugar-free carbonated form. This drink features 200 mg of caffeine, CarnoSyn beta-alanine and citrulline malate in every serving. The legendary energy and endurance that you know and love from C4. Beverage Type: Energy Drink; Flavor: Assorted; Product Packaging: Can; Volume Capacity: 16 oz.. C4 Energy Drink now available in a delicious and sugar-free carbonated form. This drink features 200 mg of caffeine, CarnoSyn beta-alanine and citrulline malate in every serving. The he legendary energy and endurance that you know and love from C4.