Citrulline ethyl ester - formed in the esterification process (of alcohol on the amino acid citrulline), facilitating the bioavailability of citrulline and reducing its consumed dose. Citrulline is an amino acid that does not build endogenous proteins. In addition to arginine and ornithine, has a leading role in the urea cycle, causing the elimination of ammonia, which is a byproduct of the metabolism of amino acids. It is a precursor to arginine, processed to form nitrous oxide and supports the metabolism occurring with the participation of arginine. It is a valued component of advanced supplements for athletes.