Glutamine is the most abundant free amino acid in the body. Tissues that require glutamine such as the immune system, gastrointestinal tract, kidneys, and liver obtain glutamine as needed from the blood. Although traditionally classified as a non-essential amino acid, glutamine is essential for maintaining intestinal function, immune response, and amino acid homeostasis during times of severe stress. Glutamine has been used for depression, moodiness, irritability, anxiety, insomnia, short bowel syndrome, Crohn's disease, and enhancing exercise performance. It has also been used for HIV / AIDS- related wasting, and mucositis.
