L-Glutamine is an amino acid that occurs most abundantly in the body by being released from muscles under stress. Aside from increasing the immune system’s efficiency to fight diseases, it also takes care of the normal functioning of the brain and the digestive system through the removal of excess ammonia in the body. A number of factors, such as stress, infections, injuries and surgery affect the levels of glutamine in the system, showing that the healing process is under way. Glutamine supplements may be used by regular exercisers to help in the recovery of muscular fitness after a workout. Glutamine, however, is known to be linked with infections of the intestine and users are advised to seek advice from professionals before ingesting this amino acid.