Science-Based Nutrition Helps Boost Nitric Oxide (NO) Levels to Support Overall Cardiovascular Health Dietary Supplement Vegan Non-GMO - Gluten Free - Soy Free 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 heling 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. Helps boost nitric oxide (NO) levels to support overall cardiovascular health. Helps support immune system. Helps support athletic endurance. Helps support recovery from athletic performance.