L-Alanyl-L-Glutamine (alanylglutamine) is a dipeptide molecule, consisting of L-glutamine and L-alanine, two amino acids.
Alanylglutamine is sometimes supplemented before prolonged physical exercise to enhance electrolyte absorption and improve endurance.
Preliminary rodent evidence suggests alanylglutamine is more effective at increasing muscular glutamine content after supplementation than glutamine itself. This is because glutamine is absorbed by the liver and intestines after supplementation. Since alanylglutamine is a dipeptide molecule, it contains more than one amino acid for the intestines to absorb, allowing glutamine to reach the muscles.
Though alanylglutamine supplementation results in greater glutamine muscular content, this has not been shown to provide a performance enhancing effect.
Current evidence suggests alanylglutamine may be a more effective supplement than glutamine because of its increased stability and water solubility, but more research is needed to determine if it actually has an effect on performance.