A Guide to Glutamine and Its Benefits

Medically Reviewed By Jared Meacham, Ph.D., RD, PMP, CSCS
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Glutamine is one of the amino acids your body uses to function correctly and fuel a range of important processes. It is often thought of as a key fuel for the immune system. Glutamine is an amino acid that has many benefits for the body. This includes benefits related to gut function and immune cells, according to 2018 research. In some cases, glutamine supplements can be beneficial for individuals who do not have enough of this amino acid.

This article will look into the functions of glutamine in the body, where the body gets glutamine from, the benefits of glutamine, how it can interact with medications, and when you might need glutamine supplements.

What is glutamine? 

a person is taking glutamine
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Glutamine is an amino acid, which is a building block for proteins in cells and tissue. It is very prevalent in the body and has many possible functions. It is incredibly important in processes related to metabolism.

The body can also use glutamine to help maintain the integrity of the body’s cells.

What does glutamine do to the body?

Glutamine is thought to be a key fuel for the immune system.

Cells involved in the immune system such as lymphocytes are generally thought to use glutamine at similar rates as glucose in conditions such as sepsis and burn recovery. Because of this, healthcare professionals often give glutamine to people before and after operations to aid the body’s immune function.

Learn more about amino acids.

Sources of glutamine

Glutamine is generated in the body naturally and is primarily stored in the muscles and lungs. It can also be found in foods rich in vegetable and animal protein, including:

  • barley
  • corn
  • egg whites
  • milk
  • peanuts
  • soybeans
  • wheat

Benefits of glutamine

Glutamine can bring a variety of benefits to the body.

For gut function

The small and large intestines consume large amounts of glutamine to function, making it a key part of gut function. In fact, in terms of energy, glutamine is more important than even glucose to the gut. 

Learn more about supplements for gut health.

For immune cells

Glutamine also significantly benefits the function of immune cells. Immune cells such as lymphocytes use glutamine at a similar rate as glucose under carbolic conditions, such as burn recovery and sepsis, to fuel the body’s immune system.

This makes it a vital fuel for the body’s immune system. For this reason, healthcare professionals often give glutamine to people before and after surgery to help improve their immune function and recovery.

For fuel and recovery

As well as being the main fuel for the immune system, glutamine is also a key fuel for high intensity exercise. It is believed that glutamine can speed recovery after exercise and can prevent infections in athletes following events.

Risks and side effects of glutamine supplementation

While glutamine has several benefits to the body, there are potential risks and side effects of glutamine supplements. The side effects of glutamine consumption include:

In addition, high levels of glutamine in blood plasma can be associated with liver failure, 2020 research suggests. As a result, liver damage can be considered a possible side effect of glutamine supplements.

Glutamine deficiency

Glutamine deficiency can be due to physical stress, experts say. This is because the body can find it difficult to create enough glutamine to meet the increased demands of stress.

This physical stress includes injuries, surgery, infections, and high intensity exercise. In addition, diseases that involve muscle wasting, such as HIV, can also increase the risk of glutamine deficiency. This is due to muscle tissue being the main source of glutamine creation in the body.

Precautions of glutamine

Before taking glutamine, you should consult your doctor or pharmacist. Tell them which other medications you are taking in case of a potentially negative interaction between them.

Additionally, if you are already taking glutamine and become pregnant, plan to become pregnant, or are nursing, consult your doctor right away. 

Interactions of glutamine

Glutamine can have a negative interaction with the medication lactulose, reducing the ammonia-lowering effect of the drug. However, this does not apply in cases where lactulose is used as a laxative.

Be sure to consult your doctor before taking glutamine so that they can establish the best practice for your situation.

Recommended dosage of glutamine

Dosages for glutamine supplements can vary from person to person. Some people take a fixed dose of 20–35 grams (g) daily, or an adjusted dose of typically 0.3 g to 0.5 g per kilogram of their body weight.

You can take glutamine by mouth or via parenteral routes, such as through an intravenous line. While delivery directly into the bloodstream does cause a greater increase in plasma glutamine than taking it orally, doctors will recommend this only if you medically require glutamine.

Frequently asked questions

Here are some frequently asked questions regarding glutamine.

When should you take glutamine?

Glutamine supplements are often given to people before and after an operation to help them recover from infections. They are also taken by elite athletes to restore immune function.

In addition to this, glutamine is used in a variety of ways to aid people with cancer. It can help treat weakness and muscle mass loss, nausea, and neuropathy from cancer treatments, such as chemotherapy

Should I take glutamine every day?

How often you take glutamine will depend on your reason for taking it, as well as other factors such as the dosage of the pill itself. Your doctor can advise you on the best practices for taking glutamine if you need to or wish to.

How do I know if I need L-glutamine?

For most people, the glutamine they receive as a part of a balanced diet and that their body produces is sufficient, according to 2018 research.

However, your doctor may recommend glutamine supplements under a number of circumstances, including as part of your care before and after surgery.


Glutamine is a vital amino acid, generated by the body and also found in foods rich in vegetable and animal protein. It provides significant benefits to the immune system, gut function, and people who perform high intensity exercise.

While a typical balanced diet has enough glutamine, doctors can recommend glutamine supplements for a variety of conditions and needs, including people having surgery and people experiencing certain side effects of some cancer treatments.

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Medical Reviewer: Jared Meacham, Ph.D., RD, PMP, CSCS
Last Review Date: 2022 Nov 29
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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  2. Glutamine. (2022). https://www.mskcc.org/cancer-care/integrative-medicine/herbs/glutamine
  3. Glutamine. (n.d.). https://restorativemedicine.org/library/monographs/glutamine/
  4. Hatami, B., et al. (2020). Glutamine powder-induced hepatotoxicity: It is time to understand the side effects of sports nutritional supplements. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7069532/