Chemical Warfare's L-Citrulline boosts nitric oxide production in the body. Nitric oxide helps your arteries relax and work better, which improves blood flow throughout your body. This amino acid is considered nonessential, meaning that your body can naturally produce some on its own. However, you can increase your levels by eating certain foods containing citrulline or by taking a supplement. These higher levels may produce beneficial effects on health and exercise performance.