Doctor’s Best L-Arginine supplies an amino acid vital in the synthesis of nitric oxide, which is an essential compound that helps blood circulation. Arginine-derived nitric oxide benefits wound healing and overall circulation, and has been shown to help increase mental acuity, immune function, and memory. Research suggest that L-Arginine supplementation helps increase muscle mass and may also positively be beneficial in improving endurance as it is a precursor to creatine, which helps supply energy to all cells of the body.