C4 was the blast heard around the world when it launched in 2011. It's helped gym junkies, weekend warriors and competitive athletes everywhere rise to become their own versions of legendarY, The Fourth Generation C4 is the next level of innovation and refinement. Its formula is now more dialed in, more potent and includes the breakthrough ingredient, TeaCorTM for improved energy that comes on quickly and lasts longer. The C4 formula includes ingredients that help promote energy, pumps and performance. Beta Alanine: An amino acid that supports muscular endurance. Beta Alanine produces a tingly sensation throughout the body that lets you know it is working.