first blood

Citrulline is a non-essential, non-protein amino acid that forms during the urea cycle and forms ornithine when combined with carbon dioxide. Citrulline is also a critical source of endogenous (natural) arginine, as it is rapidly and efficiently converted to arginine in the vascular endothelium and other tissues. Citrulline’s benefits have been shown to be greater than its parent compound. While arginine undergoes direct hepatic (liver) metabolism through the enzyme arginase, citrulline bypasses hepatic metabolism entirely and it is delivered straight to the bloodstream. The result is that gut absorption and plasma (blood) bioavailability studies comparing citrulline and arginine have shown two things. First, citrulline is less readily destroyed and has greater absorption than arginine. Second, citrulline supplementation increases arginine levels more effectively than arginine supplementation itself. This translates to promising results. For example, animal studies show a signif