Nitric Oxide Precursor Increased Vasodilation Enhanced Recovery Dietary Supplement L-Arginine: The Science L-Arginine is a conditionally essential amino acid that acts primarily as a nitric oxide precursor. During training, calcium release causes the blood vessels to utilize the nitric oxide synthase enzymes to created nitric oxide from available L-Arginine, thus relaxing and causing vasodilation. By supplying an adequate supply of L-Arginine, you will help maximize the potential nitric oxide production for enhanced vasodilation resulting in enhanced muscle pumps, oxygen utilization and nutrient delivery. Key Benefits of L-Arginine: Potent Precursor of Nitric Oxide Production Promotes Muscle Protein Synthesis Supports Vasodilation & Muscle Pumps Natural Precursor to Creatine Synthesis Helps Improve Muscle Recovery