PROLINE’s Pharmaceutical Grade 100% PURE GLUTAMINE™ is the most abundant amino acid in the body comprising more than 60% of the free amino acid pool in skeletal muscle & greater than 20% of total circulating amino acids. After training, you deplete your glutamine concentrations by 40% triggering muscle catabolism, Glutamine counteracts this & helps you repair muscle cells quickly & maintains optimal muscle function. L-Glutamine may help reduce muscle soreness & rebuild muscle tissue.