Although considered a “non-essential” amino acid, glutamine is considered a “brain food” and helps build and maintain muscles (useful in weight loss and bodybuilding). It has been used treat arthritis, autoimmune diseases, fibrosis, intestinal disorders, ulcers, connective tissues disease, tissue damage from chemotherapy/radiation treatments, fatigue, impotence, schizophrenia and senility.

Glutamine is utilized as a source of energy and for nucleotide synthesis by all rapidly dividing cells, such as the cells of the intestinal lining and certain immune cells (thymocytes, lymphocytes and macrophages). Without sufficient glutamine, the intestines atrophy and the immune function breaks down.

In the brain, glutamine is a substrate for the production of both excitatory and inhibitory neurotransmitters (glutamate and GABA). Glutamine is also an important source of energy for the nervous system. If the brain is not receiving enough glucose, it compensates by increasing glutamine metabolism for energy, thus the popular perception of glutamine as “brain food” and its use as a pick-me-up. Glutamine users often report more energy, less fatigue and better mood.

Glutamine also plays a part in maintaining proper blood glucose levels and the right pH range. The body has an exquisite mechanism for maintaining pH homeostasis. If the pH of the blood is too acidic, more glutamine is directed to the kidneys, where a certain type of glutamine results in the release of bicarbonate ions to correct acidosis. If the pH is too alkaline, more glutamine is sent to the liver, where a different kind of metabolism releases hydrogen ions to correct alkalosis.

Glutamine is plentiful in both animal and plant protein. The typical American diet provides between 3.5gm and 7gm of glutamine. Glutamine is the most abundant free amino acid in the serum, muscle and cerebrospinal fluid. It constitutes 50% of all amino acids in the serum, and more than 60% of free amino acids within the body.

Most clinicians who are using the L-glutamine to support repair of the intestinal tract are recommending that this supplement be taken on an empty stomach. If however, significant intestinal problems are noted when taken alone then using with foods may be better tolerated.

The major use for high-dose glutamine would be to repair gastrointestinal injury. In such cases, short-term use is advised.

Glutamine has recently been shown to produce extreme hypoglycemia, even more so than leucine, which is known to produce fatal hypoglycemia in infants.

The reason Chinese Restaurant Syndrome is not seen with glutamine challenge is that the glutamate receptors in the lungs and esophagus are stimulated by glutamate, not glutamine. The glutamine must be converted first and this occurs primarily in the brain.

The only safe situation for long-term glutamine use is in the vigorous athlete. Glutamine is used as a muscle fuel, so that vigorous exercise will consume most of the glutamine before it can accumulate in the brain.


Glutamine can help with the following



Alcohol-related Problems

Alcohol inhibits glutamine synthase which partly explains the neurotoxicity of alcohol.


Parkinson's Disease / Risk

Raising glutathione levels (a potent antioxidant and detoxifier) will provide a protective effect.


Alzheimer's Disease

Glutamine accumulation has also been found in Alzheimer’s disease, Huntington’s disease and high levels of brain glutamine have been associated with a worse prognosis in Lou Gehrig’s disease. Likewise, recent studies have shown that high brain glutamine levels increase brain levels of free radicals and impair the ability of brain mitochondria to produce energy. When the brain produces low energy, excitotoxins, such as glutamate, become even more toxic. It has been shown that the reason for glutamine toxicity under these conditions is because it is converted to the excitotoxin – glutamate. Russell L. Blaylock, M.D.


Gluten Sensitivity / Celiac Disease

Glutamine is the preferred fuel of small intestine cells. Supplemental glutamine may promote a faster recovery time once a gluten-free diet is begun.


Amyotrophic Lateral Sclerosis (ALS)

Please see the link between Alzheimer’s and Glutamine.


Multiple Sclerosis / Risk

Of particular concern is the finding that people with multiple sclerosis have increased levels of the enzyme glutaminase (the enzyme that converts glutamine into glutamate) in areas of nerve fiber damage. High levels of glutamine in the diet would increase glutamate levels near these injured areas magnifying the damage. It has been shown that excitotoxicity plays a major role in multiple sclerosis by destroying the cells (oligodendrocytes) that produce myelin. Russell L. Blaylock, M.D.


Crohn's Disease

Although glutamine is known to play a role in small intestine function, in Crohn’s disease at least two studies have shown it to be mildly harnful. [J Parenter Enteral Nutr 24:196, 2000]



Increased Intestinal Permeability / Leaky Gut

People who use glutamine enhance the health of their intestinal lining. They will be less concerned about leaky gut syndrome and the consequences of allergies, the “leaking out” of pathogens and possible arthritis. Glutamine used to be called the “intestinal permeability factor.” Glutamine is the chief source of energy for the cells which line the intestines. Most glutamine in the diet is metabolized by the intestines, helping to maintain the structural integrity of the its lining and supporting its quick cellular turnover.


Gastric/Peptic Ulcers

Fresh cabbage juice has for a long time been used successfully against ulcers, probably due to its glutamine content. The amino acid glutamine works over time in doses as low as 500mg tid to heal stomach and small intestine lesions. A study of ulcers found that 1600mg of glutamine per day had a 50% cure rate within 2 weeks and 92% within 4 weeks.

Drug Side Effects  

Radiation, Side-Effects

In high doses, glutamine helps prevent the devastating damage to the gastrointestinal tract that results from radiation therapy.


Chemotherapy Side-Effects/Risks

In high doses, glutamine helps prevent the devastating damage to the gastrointestinal tract that results from chemotherapy.


Overtraining, Effects

The amino acid glutamine is believed to counteract exercise-induced immune system suppression. In one study, 200 runners and rowers consumed either a glutamine-containing drink or placebo drink. The percentage of athletes who reported no infections was 81% in the glutamine group and 49% in the placebo drink.


Low HGH (Human Growth Hormone)

It has been shown that GH is adequately produced by the aging pituitary, but its secretion from the pituitary is down-regulated with age. Scientists have found that certain amino acids and vitamins can stimulate the natural release of GH from the pituitary in many people.

Some amino acids have been shown to stimulate GH release, and may be found in preparations designed to increase GH release. Most of these preparations come with the recommendation that they be used just prior to muscle building exercise for maximal effect. These amino acids include: L-arginine, L-lysine, L-glutamine, L-ornithine, and glycine.

The Immune System  

AIDS / Risk

A pilot double-blind study of glutamine for intestinal problems in PWAs did not produce statistically significant results, quite possibly because the highest dose used was only 8 grams and most researchers now recommend doses higher than 20 grams for acute problems. However, it did show a trend towards improvement in those on higher doses. Studies of people with other conditions have found that glutamine supplementation speeds recovery and can even restore firm, healthy stools to people who have only inches (of a former 21 feet!) of intestine remaining.

Most people think the intestine is just an organ needed for the elimination of waste, but in fact, it is a crucial part of the immune system. Like people with HIV, cancer patients on chemotherapy often suffer severe diarrhea. Charles Smigelski, RD, a nutritionist and researcher at Harvard University, reports seeing a cancer chemo patient who had disabling diarrhea for six months. Within a week on glutamine, his bowel movements were normal.

Smigelski is high on glutamine and other anti-oxidant supplements for people with HIV. He has about 100 HIV patients in his practice that are supplementing with glutamine and says, Most people report that they feel better on every level. It improves their energy, it reduces diarrhea, and it’s hugely useful in wasting and dealing with oxidative stress. A ton of people swear by it. []




To produce enough GABA, people need an abundant supply of the amino acid glutamine – glutamine is the nutritional precursor of GABA which has an antianxiety effect. [Acta Paediatr Jpn Oversea Ed (Tokyo) 20(1978): pp.11-23] In another study, people taking glutamine showed significant reductions in their feelings of anger and fatigue. [Rogers, et. al., Effects of Glutamine on IQ, Tex. Rep. Biol. Med. 5]



Glutamine supplementation has been proven to help decrease depression and reduce anxiety.


Attention Deficit Disorder (ADD / ADHD)

When children are deficient in GABA, they often feel the same anxiety and restlessness that makes adults drink, crave sweets or succumb to food binges. In children, though, this anxiety and restlessness is often labeled as Attention Deficit Disorder, or ADD. [Control Hyperactivity A.D.D. Naturally, by B.J. Sahely, Ph.D., C.N.C, p.46-47] Glutamine can increase the ability to concentrate for extended periods.

Other sources suggest tha glutamine may be contraindicated in ADHD. Russell L. Blaylock, M.D.


Problem Caused By Being Underweight

Glutamine is one of the favorite supplements of body builders and others who exercise a lot. Strenuous exercise such as weight lifting causes tiny injuries to the muscle tissue. By donating nitrogen, glutamine helps build proteins and repair the muscle, as well as help build up more muscle. Part of its muscle-building action may be due to its ability to induce the release of growth hormone. Serious fitness fans take glutamine both before and after workout. Taking 2-3gm after workout is particularly recommended.



Glutamine plays a vital part in the control of blood sugar. It helps prevent hypoglycemia , since it is easily converted to glucose when blood sugar is low.

Nervous System  

Huntington's Disease

Please see the link between Alzheimer’s and Glutamine.

Organ Health  

Fatty Liver

Glutamine is beneficial for the liver, since it cleanses the liver of the waste products of fat metabolism, and helps prevent fatty buildup. It can aid in the treatment of early-stage cirrhosis. Once liver damage is advanced, however, glutamine cannot help since the liver can no longer metabolize it properly.


Cirrhosis of the Liver

Individuals with liver toxicity tend to accumulate ammonia in their blood and brain. Until recently, it was assumed that it was the ammonia that caused liver disease-associated brain injury and that glutamine was protective. Newer studies indicate that actually it is the glutamine that is causing the brain’s injury. Increasing glutamine in the diet would significantly aggravate this damage. Russell L. Blaylock, M.D.


Diabetes Type II

Diabetics should exercise caution with supplemental glutamine since they have an abnormal glutamine metabolism. An increased production of glucose from glutamine is probably related to excess levels of glucagon, usually seen in diabetics.

Diabetics also have poor functioning of the retinal glia cells. The diabetic retina is prone to damage through glutamate excitotoxicity, since the glia are not converting enough glutamate to glutamine.


Increased Risk of Alzheimer's / Dementia

Glutamine accumulation has also been found in Alzheimer’s disease, Huntington’s disease and high levels of brain glutamine have been associated with a worse prognosis in Lou Gehrig’s disease. Likewise, recent studies have shown that high brain glutamine levels increase brain levels of free radicals and impair the ability of brain mitochondria to produce energy. When the brain produces low energy, excitotoxins, such as glutamate, become even more toxic. It has been shown that the reason for glutamine toxicity under these conditions is because it is converted to the excitotoxin – glutamate. Russell L. Blaylock, M.D.


Possible Pregnancy-Related Issues

Glutamine passes through the placenta and may actually be concentrated in the baby’s blood, producing very high levels. Glutamate plays a major role in the development of the baby’s brain. Excess glutamate has been shown to cause significant impairment of brain development in babies and can lead to mental retardation.


May do some good
Likely to help
Highly recommended
May have adverse consequences


Amino Acid

An organic acid containing nitrogen chemical building blocks that aid in the production of protein in the body. Eight of the twenty-two known amino acids are considered "essential," and must be obtained from dietary sources because the body can not synthesize them.


A non-essential amino acid, glutamine is considered to be a brain fuel. Glutamine has been used therapeutically for alcoholism, mild depression and to reduce the craving for sweets. Glutamine is very important in the functioning of the metabolism and muscle maintenance. Glutamine supplementation can help prevent muscle and other tissue breakdown by providing the body with nitrogen and fuel.


Inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis. Osteoarthritis, the most common form, is characterized by a gradual loss of cartilage and often an overgrowth of bone at the joints.

Autoimmune Disease

One of a large group of diseases in which the immune system turns against the body's own cells, tissues and organs, leading to chronic and often deadly conditions. Examples include multiple sclerosis, rheumatoid arthritis, systemic lupus, Bright's disease and diabetes.


Lesion on the skin or mucous membrane.


A treatment of disease by any chemicals. Used most often to refer to the chemical treatments used to combat cancer cells.


Any of a group of psychotic disorders usually characterized by withdrawal from reality, illogical patterns of thinking, delusions, and hallucinations, and accompanied in varying degrees by other emotional, behavioral, or intellectual disturbances. Schizophrenia is associated with dopamine imbalances in the brain and defects of the frontal lobe and is caused by genetic, other biological, and psychosocial factors.


Chemicals in the brain that aid in the transmission of nerve impulses. Various Neurotransmitters are responsible for different functions including controlling mood and muscle movement and inhibiting or causing the sensation of pain.


The amino-acid derivative GABA (Gamma-Aminobutyric Acid) is a calming substance. Tranquilizers like Valium and Librium owe their soothing effects to the fact that they stimulate GABA receptors in the brain.

Nervous System

A system in the body that is comprised of the brain, spinal cord, nerves, ganglia and parts of the receptor organs that receive and interpret stimuli and transmit impulses to effector organs.


A sugar that is the simplest form of carbohydrate. It is commonly referred to as blood sugar. The body breaks down carbohydrates in foods into glucose, which serves as the primary fuel for the muscles and the brain.


The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds.


A measure of an environment's acidity or alkalinity. The more acidic the solution, the lower the pH. For example, a pH of 1 is very acidic; a pH of 7 is neutral; a pH of 14 is very alkaline.




Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.


(gm): A metric unit of weight, there being approximately 28 grams in one ounce.


The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.


A hollow, muscular, J-shaped pouch located in the upper part of the abdomen to the left of the midline. The upper end (fundus) is large and dome-shaped; the area just below the fundus is called the body of the stomach. The fundus and the body are often referred to as the cardiac portion of the stomach. The lower (pyloric) portion curves downward and to the right and includes the antrum and the pylorus. The function of the stomach is to begin digestion by physically breaking down food received from the esophagus. The tissues of the stomach wall are composed of three types of muscle fibers: circular, longitudinal and oblique. These fibers create structural elasticity and contractibility, both of which are needed for digestion. The stomach mucosa contains cells which secrete hydrochloric acid and this in turn activates the other gastric enzymes pepsin and rennin. To protect itself from being destroyed by its own enzymes, the stomach’s mucous lining must constantly regenerate itself.


Pertaining to the stomach, small and large intestines, colon, rectum, liver, pancreas, and gallbladder.


A condition characterized by an abnormally low blood glucose level. Severe hypoglycemia is rare and dangerous. It can be caused by medications such as insulin (diabetics are prone to hypoglycemia), severe physical exhaustion, and some illnesses.


A white, crystalline amino acid essential for optimal growth in infants and nitrogen equilibrium in adults. It cannot be synthesized by the body and is obtained by the hydrolysis of food protein during pancreatic enzyme digestion.


Commonly called the "food pipe", it is a narrow muscular tube, about nine and a half inches long, that begins below the tongue and ends at the stomach. It consists of an outer layer of fibrous tissue, a middle layer containing smoother muscle, and an inner membrane, which contains numerous tiny glands. It has muscular sphincters at both its upper and lower ends. The upper sphincter relaxes to allow passage of swallowed food that is then propelled down the esophagus into the stomach by the wave-like peristaltic contractions of the esophageal muscles. There is no protective mucosal layer, so problems can arise when digestive acids reflux into the esophagus from the stomach.

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