Amino acids are the building blocks that form body and dietary proteins. Twenty-two different amino acids occur in nature and have traditionally been grouped into two categories–nonessential and essential. Nonessential amino acids are made by the liver from general dietary protein intake and don’t have to be consumed directly. In contrast, essential amino acids cannot be made “from scratch” by the liver and therefore must come from diet or supplements to meet the body’s daily demands.

Glutamine has traditionally been considered a “non-essential” amino acid, but current research suggests that it may be “conditionally essential” under certain metabolic conditions such as exercise.

BRAIN FUEL – Glutamine crosses the blood /brain barrier readily and is converted into Glutamic acid in the brain. As a key neurotransmitter it helps increase mental function, alertness, and exerts a mild anti-depressant effect.

INTESTINAL HEALTH – Glutamine is the major source of energy for cells in the GI tract. The gut or any other of the mucous membranes respond exceptionally well to glutamine, which helps to heal mucosal tissue.

STRESS AND TRAUMA – when individuals are metabolically stressed, they become catabolic, which means that their tissue is breaking down. Increased stress or injury dramatically increases glutamine usage and excretion. Supplemental glutamine can help support muscle tissue and prevent muscle wastage and breakdown.

LIVER DETOXIFICATION – glutamine acts as a nitrogen shuttle helping reduce the formation of toxic levels of ammonia in the liver. Glutamine is also required by the liver to manufacture glutathione a potent antioxidant.

IMMUNE BOOSTER – glutamine has been shown to stimulate lymphocytes, phagocytes and antibody IgA (keeps bacteria from entering the body) activity. Data shows that optimal glutamine levels are crucial in preventing immunosuppression in burns patients. Autoimmune conditions can benefit from glutamine administration due to glutathione production reducing harmful cytokine activity.

SPORTS PERFORMANCE – glutamine can offer a variety of benefits for athletes; through supporting muscle tissue maintenance, stress control, and immune support.

PAIN – Glutamine has been found to be almost as effective as phenylbutazone (similar to aspirin) in reducing pain, inflammation and swelling.

Dosage range: 1tsp (3.5 g) – 2 tsp daily or as recommended by a healthcare practitioner.

Potential applications: sports nutrition, stress management, detoxification, ‘leaky gut’ syndrome, mouth, stomach or intestinal ulcers, diarrhea, inflammatory bowel disease, ulcerative colitis, Crohn’s disease, IBS, alcoholism, surgery and post surgical recovery, mental ‘sharpness.’

Known contraindications: patients with severe liver disease should avoid glutamine supplementation.

Useful links: Glutamine can be used alongside flavonoids such as grape seed extract or quercetin, and chlorophyll rich green foods to aid with intestinal repair.

Note: Take away from protein for maximum affect, ideally 30-60 minutes before or after a meal


1. Keast, D., Arstein, D., et al. “Depression of plasma glutamine concentration after exercise stress and its possible influence on the immune system.” Med J Aust, 162: 15-8, 1995. 2. MacLennan, P.A., Smith, K., et al. “Inhibition of protein breakdown by glutamine in perfused rat skeletal muscle.” FEBS Lett, 257: 133-36, 1988. 3. Welbourne, T.C. “Increased plasma bicarbonate and growth hormone after an oral glutamine load.” Am J Clin Nutr, 61: 1058-61, 1995. 4. Welbourne, T.C., & Joshi, S. “Interorgan glutamine metabolism during acidosis.” Jnl Parent Ent Nutr, 14: 775-855, 1990. 5. Rudman, D., Kutner, M.H., et al. “Impaired growth hormone secretion in the adult population: Relation to age and adiposity.” J Clin Invest, 67: 1361-69, 1981. 6. Opara, E.C., Petro A., et al. “L-glutamine supplementation of a high fat diet reduces body weight and attenuates hyperglycemia and hyperinsulinemia in C57BL/6J mice.” J Nutr, 126: 273-79, 1996.

Robert M. Hackman, Ph.D., is executive director of the Center for Complementary and Alternative Medicine Research at the University of California, Davis, and associate professor of Nutrition at the University of Oregon. His research and teaching focus on sports nutrition, weight management and optimal human performance. Hackman is an international consultant to nutrition- and health-oriented companies and professional and Olympic athletes.