Glutamine in a supplemental form can be helpful in the treatment of arthritis, autoimmune disease, fibrosis, intestinal disorders, peptic ulcers, connective tissue disease such as polymyositis, scleroderma and tissue damage due to radiation treatment for cancer. It enhances mental functioning and has been used to treat a range of problems, including developmental disabilities, epilepsy, fatigue, impotence, depression, schizophrenia, and senility. It preserves glutathione in the liver and protects that organ from the effects of acetaminophen overdose. It enhances antioxidant protection. It decreases sugar cravings, the desire for alcohol and is useful for recovering alcoholics.