Jarrow L-Glutamine FORMULAS contains L-glutamine of the highest pharmaceutical purity. L-glutamine is the most common amino acid in the human body - it is involved in many metabolic processes, including the synthesis and protection of muscle tissue and the production of glycogen. L-glutamine is also the main fuel source for enterocytes (intestinal cells), thus supporting the integrity of the intestinal mucosa. Glutamine is one of the most abundant amino acids in the blood and brain. Glutamine is an inhibitory neurotransmitter and acts as a precursor of the amino acid GABA (Gamma Amino Butyric Acid) - gamma-aminobutyric acid.