Formulated without any harmful fillers, key ingredients in our NO Booster are backed by 4 clinical studies that substantiate the effectiveness of our formula. Our elite nitric oxide booster provides a powerful combination of ingredients, based on clinical research, to help you get the most out of your workout and push your body to the next level. Features clinical-strength ingredients L-Citrulline and S7, as well as L-Arginine Alpha-Ketoglutarate, Beet Root and Pine Bark, to boost NO and help men maintain optimal levels over time. A clinical study shows an increase in nitric oxide levels by as much as 230% in just 3 hours. Boosting NO helps support healthy blood flow, cardiovascular health, and increased muscle pumps. Developed by the #1 men’s brand in GNC, Nugenix Nitric Oxide Booster is a powerful blend of several plant-based ingredients to help skyrocket your body’s own nitric oxide production within hours.