The Health Benefits of Glutamine (2025)

Glutamine is the most common amino acid (a building block of protein) in the blood. It is found in certain foods and is also available as an over-the-counter (OTC) supplement, often called L-glutamine. The body uses glutamine for energy, especially in fast-growing cells like those in the gut and immune system.

Glutamine helps move nitrogen between different parts of the body, which is important for making proteins and keeping cells working properly. Without enough glutamine, the body may have trouble healing wounds, fighting infections, and keeping muscles strong, which can lead to illness and slow recovery.

What Is Glutamine?

Glutamine is an amino acid, which are the building blocks of protein. It is the most abundant amino acid in the human body and is considered non-essential because the body makes it on its own, so you don’t need to get it from your diet.

Glutamine plays several important roles in the body. It helps your body make proteins that are needed for immune function, cell repair, and keeping the digestive system healthy. It also provides energy to cells in the brain, kidneys, and immune system, helping them work properly.

Glutamine is essential for regulating nitrogen balance in the body. Nitrogen is important because it helps build proteins, which are needed for muscle growth and repairing tissues. Glutamine helps keep the right amount of nitrogen in the body by balancing it, which is necessary for overall health.

If you don’t get enough glutamine, your immune system may weaken, making it harder to fight off infections. You could also experience slower healing of wounds, digestive problems, and muscle loss, especially during times of illness or injury.

Benefits

Glutamine offers many benefits to your body and is used constantly, not just when you're ill. Glutamine is necessary because it:

Supports the immune system: Studies have shown that only about one in three people admitted to the intensive care unit (ICU) have low glutamine levels. Glutamine is often given to people who are hospitalized to counter this, as glutamine supports healing, immune function, and recovery during times of severe illness and bodily stress.

Supports intestinal health: Glutamine helps balance gut bacteria and maintains the intestinal lining. Because of its role in gut repair, a prescription glutamine supplement called Nutrestore is used to support nutrient absorption in people with short bowel syndrome.

May boost athletic performance: Some people take glutamine to enhance exercise performance, but little evidence supports this claim. In a review of 25 clinical trials, glutamine did not affect athletic performance or body composition.

May reduce heart disease risk: Glutamine may help improve heart health by reducing inflammatory markers and supporting better metabolic function. Research shows that glutamine may support healthy blood sugar control, cholesterol levels, and inflammation, which are crucial for heart health.

Enhances wound healing: During times of stress, such as serious injuries, burns, or infections, the body may need more glutamine than it can produce. Glutamine supplements may support wound healing by reducing inflammation and speeding up recovery. Clinical trials have shown that supplementation may shorten hospital stays and help people with burns heal faster.

May prevent cancer: Many people with cancer have low glutamine levels. Glutamine supplementation may help prevent cancer by supporting healthy cell function, improving gut health, and limiting inflammation. However, its role is complex since cancer cells also use glutamine for growth, meaning its effects may depend on the type and stage of cancer.

May relieve oral mucositis: Oral mucositis (painful mouth sores) is a common side effect of cancer treatments. Some studies suggest that glutamine may not prevent mucositis but can reduce its severity, potentially reducing the need for opioid pain medication and tube feeding in people receiving radiation or chemotherapy.

Improves HIV treatment: Glutamine may help people with HIV/AIDS by making their immune system stronger when taken with antiretroviral therapy (ART). Glutamine supports gut health and reduces inflammation, which can help the body fight infections better. This could lead to better health and improved treatment results for people living with HIV.

Eases irritable bowel syndrome (IBS): Glutamine may help reduce inflammation, improve symptoms, and slow disease progression in people with IBD. More research is needed to understand how, but it's beneficial effects for gut health, intestinal health, immune function, and tissue repair likely play a large role.

Fights sickle cell disease (SCD): Glutamine is available as an FDA-approved prescription medication called Endari for sickle cell disease. This oral powder has been shown to reduce complications in people with SCD ages five and older by improving red blood cell function and flexibility. It also helps reduce vaso-occlusive crises, a painful condition where sickled cells clump together and block blood flow.

Food Sources

Glutamine is found in food, especially plant and animal protein sources. Food sources of glutamine include:

• Beef
• Pork
• Poultry
• Milk
• Yogurt
• Ricotta cheese
• Cottage cheese
• Raw spinach
• Raw parsley
• Cabbage

Glutamine is a non-essential amino acid that the body naturally produces. Most people don’t need extra from food or supplements, but during severe injury or illness, additional intake may support healing.

Supplement Use

Glutamine supplements are widely available. Most supplements are labeled as L-glutamine. You can find them in a variety of forms, including powders, capsules, tablets, or liquids. Glutamine is also found in many protein powder supplements.

Again, most people don’t need to take a glutamine supplement. Although, you may benefit from one if you have a chronic illness or do intense physical activity. If you think you would benefit from a glutamine supplement, consult a healthcare provider first, as excess glutamine is not always helpful.

Side Effects

Getting more glutamine than your body needs can cause more harm than good. Although it's rare to get too much glutamine through diet alone, taking glutamine supplements, especially in high doses, can lead to side effects.

Although uncommon, taking too much glutamine can result in:

• Swelling
• Headache
• Fever
• Nausea
• Vomiting
• Infections

Side effects associated with the glutamine drug Endari include:

• Constipation
• Nausea
• Headache
• Stomach pain
• Cough
• Back pain
• Chest pain

These side effects were seen in up to 20% of people with sickle cell disease who used prescription glutamine.

Long-term consumption of glutamine supplements has been linked to liver failure. For most people, a balanced diet provides a safe amount of glutamine without risk.

Who Should Not Take Glutamine?

Glutamine supplements aren’t suitable for everyone, so consult your healthcare provider before use. They should be avoided in the following cases:

• Pregnancy and breastfeeding: Due to limited safety data, glutamine supplements are not recommended in people who are pregnant or breastfeeding, though normal dietary intake is generally safe.
• Children: While glutamine has been studied in seriously ill children, safety data is limited, so supplements should only be used under medical supervision.
• Kidney and liver conditions: Since the kidneys process glutamine, people with kidney disorders should avoid it. People with liver failure may already have high glutamine levels and should not take additional supplements.
• Reye's syndrome: Glutamine is broken down into glutamate and ammonia. Since Reye’s syndrome can cause dangerous ammonia buildup in the blood, taking glutamine may worsen this effect and increase the risk of brain swelling (encephalopathy).
• History of seizures: People with epilepsy and other neurological conditions are often advised against taking glutamine supplements, as excess levels may overstimulate nerve activity and potentially trigger or worsen seizures.

Glutamine may interact with some herbs and medications. Consult a healthcare provider about glutamine if you take:

• Insulin and other diabetes medications: Glutamine may alter blood sugar levels and can change the amount of medicine needed for some people with diabetes.
• Dietary supplement arginine: Levels of this amino acid have increased from glutamine use.
• Cancer therapy: While glutamine has some possible benefits for people with cancer, some lab studies suggest it may stimulate tumor growth. If you are receiving cancer therapy, you should never start taking a new supplement without first consulting your healthcare provider.

Dosage

Most adults consume between 3 and 6 grams of glutamine daily from foods.

While there is no recommended dosage for oral glutamine supplements, studies have used the following glutamine doses:

• 21 to 30 grams for inflammatory bowel disease
• Up to 45 grams a day for six weeks for strength training

The FDA has approved the following recommended doses for prescription medications that contain glutamine:

• Endari: 5 to 15 grams twice a day, mixed in 8 ounces of liquid or 4 to 6 ounces of food, for sickle cell complications
• Nutrestore: 5 grams taken six times a day, mixed in 8 ounces of water, for short bowel syndrome

Adult glutamine doses of up to about 30 grams a day seem to be well-tolerated. Do not mix glutamine with hot water, as this causes it to break down.

Summary

Glutamine is an amino acid made in the body, and most healthy people get enough through protein-rich foods like beef, tofu, and eggs. However, supplementation may be necessary for some, especially under the guidance of a healthcare provider.

People with severe burns or undergoing cancer treatment may benefit from glutamine supplementation. While the FDA has approved prescription products like Endari and Nutrestore, over-the-counter glutamine supplements have not been approved.