Nitra flex +C contains unique ratios of scientifically validated compounds that help you remain alert, intense and focused. Creapure Creatine Monohydrate drives increased power output, muscle endurance and muscle volumization. Physiological Basis Reactive hyperemia describes the increase in muscle blood flow that occurs during high-intensity resistance exercise and produces the pump associated with increases in muscle size. NITRAFLEX+ Creatine pre-training formula contains ingredients that in vitro, animal and clinical studies suggest possess properties that may help advanced athletes maximize energy, intensity, vascularity and reactive hyperemia (pumps) during their workouts and provide long-term support of testosterone and nitric oxide levels in the healthy range when used as directed. Comes in delicious flavors of lemon lime.