Some people use glutamine for digestive system conditions such as stomach ulcers, ulcerative colitis, and Chron's disease. It is also used for depression, moodiness, irritability, anxiety, insomnia, and enhancing exercise performance.lutamine is POSSIBLY SAFE for most adults when taken by mouth in doses up to 40 grams daily, and when used intravenously (by IV) in doses up to 600 milligrams per kilogram of weight daily. Children: Glutamine is POSSBILY SAFE when taken by mouth appropriately.