L-Glutamine plays an important role in many bodily functions such as protein synthesis, brain function, intestinal health, blood sugar, and energy levels. It converts more quickly into glucose than other amino acids and therefore helps maintain healthy blood sugar levels.
Because it can pass the blood-brain barrier, it is known as brain fuel. In the brain it is converted to glutamic acid which is essential for cerebral function. Glutamine is found in large amounts in the muscles and is readily available when needed for the synthesis of skeletal muscle proteins. Because this amino acid helps build and maintain muscle, supplemental glutamine is useful for dieters and persons doing strength-training exercises.