Glutamine is the most abundant amino acid in the organism and it is involved in more metabolic processes than any other amino acid. Glutamine is converted to glucose when more glucose is required by the body as an energy source. It serves as a source of fuel for cells lining the intestines. Glutamine is also used by white blood cells and important for immune activity.

In animal studies, glutamine has shown to promote anti-inflammatory activity. Glutamine in combination with N-acetylcysteine (NAC) supports the synthesis of glutathione, a naturally occurring and important antioxidant that it is believed to be protective with HIV infections. Evidence suggests that a megadose of glutamine supplementation increases the survival rate of people with illnesses.

Glutamine can be found in many foods high in protein, such as fish, meat, beans, and dairy products. Healthy people should acquire l-glutamine from food sources. Supplementation is recommended for people with an illness.