Even Stronger Than C4 Original Contains Arginine for Added Pumps Promotes Enhanced Focus and Endurance 300mg of Caffeine to Help You Push Through Your Workout If you need an extra boost to your workout, Cellucor has you covered, with C4 Extreme. Its formula contains more than twice as much caffeine as C4 Original, making it perfect for those with a higher caffeine tolerance. This formula also makes use of Teacrine, which adds an even larger energy boost, without the jitters and overstimulation that an even larger amount of caffeine may produce. Work out even longer, as the beta alanine assists in increasing your endurance. Get more out of your training, with C4 Extreme!