Glutamine powder scoop with barbell

Does L-Glutamine Boost Immunity and Improve Gut Health?

L-glutamine is one of those supplements that has been around for decades.  It’s one of the most popular amino acids and is commonly found in protein powders, pre-workouts, and BCAA products.

Although there is a lot of conflicting information about how well L-glutamine affects athletic performance or weight loss, one area that everyone agrees on is that L-glutamine plays an important role in gut health and immune function.

In this article, we'll take a look at L-Glutamine and its effects on immunity and gut health to help you decide if it's worth adding to your supplement regimen.

What is L-Glutamine?

L-glutamine, sometimes simply referred to as glutamine, is an amino acid that is produced by the body. According to Healthline, its main purpose is to serve as building blocks for proteins.

It is considered a "non-essential" amino acid because the body can make it on its own. However, during times of stress, such as when you are sick or working out hard, your body may not be able to make enough L-glutamine and you might need to get it from your diet.

L-glutamine is found in high concentrations in several foods and is also sold in powder form and can be taken as a supplement.

Health Benefits of L-Glutamine

L-glutamine has been studied for several decades due to its role in our body's production of protein. In recent years, however, researchers have begun to focus on its potential health benefits, specifically with regard to immunity and gut health.

Some of the potential health benefits of L-glutamine include:

  • recovery from major injuries like burns and surgery
  • protecting against a leaky gut
  • boosting immunity
  • improving recovery after intense exercise
  • involuntary weight loss in people with HIV/AIDS

L-glutamine has also been approved by the FDA as a prescription for sickle cell disease.

Because of its role in forming proteins, L-glutamine has gotten a reputation for improving athletic performance and muscle growth. Researchers have studied whether or not it could be used in a way similar to protein supplements, but not enough research exists to support this suggestion.

Instead, L-glutamine is more useful for athletes as a way to support their overall health and well-being so they can train harder and perform at their best.

Side Effects

L-glutamine is considered safe and has fairly mild side effects. According to WebMD possible side effects include:

  • bloating
  • nausea
  • dizziness
  • heartburn
  • stomach pain

Although L-glutamine naturally occurs in the diet, not enough research has been done on women who are pregnant or breastfeeding to know if it is completely safe. Therefore, it is best to avoid taking it unless prescribed by your doctor.

It's also recommended to avoid taking L-glutamine if you have:

  • liver disease
  • bipolar disorder
  • monosodium glutamate (MSG) sensitivity
  • seizures

How Does L-Glutamine Affect Immunity?

One of the most exciting benefits of L-glutamine is its ability to boost immunity.

One study found that "Immune cells largely depend on glutamine availability to survive, proliferate, and function, and ultimately defend our body against pathogens."

In other words, L-glutamine is essential for the proper functioning of our immune cells. Without it, they would not be able to do their job properly and we would be more susceptible to infection.

This is especially true during times of stress, such as when we are sick or recovering from an injury. During these times, our body depletes our natural stores of glutamine.

This is when it can be beneficial to consume additional amounts of L-glutamine to help our immune cells function properly and keep us healthy.

How Does L-Glutamine Improve Gut Health?

Because it serves as an energy source for intestinal and immune cells, L-glutamine plays an important role in gut health. When the lining of the intestines becomes damaged bacteria and toxins can "leak" through into the bloodstream.

This can lead to inflammation throughout the body and an increased risk for infections.

L-glutamine has been shown to help repair a "leaky gut" by strengthening the barrier between the intestines and the bloodstream. It also helps the normal growth and maintenance of intestinal cells.

Sources of L-Glutamine

If you're looking to increase the amount of L-glutamine in your diet, you're in luck, because it naturally occurs in many different foods.

According to nutritionist Donia Hilal, here are some good sources of L-glutamine:

  • fish and seafood
  • red cabbage
  • dairy: milk, cheese, yogurt
  • eggs
  • nuts and seeds
  • soya
  • dark leafy greens
  • red kidney beans
  • seaweed
  • meat

Most people are able to easily meet their L-glutamine needs with a healthy diet. If, however,  you are under a lot of stress or have a health condition that depletes glutamine stores, you may benefit from taking a supplement.

Talk to your doctor before starting any new supplement, especially if you have a medical condition.

FAQs About L-Glutamine

Here are some frequently asked questions about L-glutamine and its role in boosting immunity and improving gut health.

What is the difference between l-glutamine and glutamine?

Glutamine is the amino acid produced by the body. L-glutamine is a form of glutamine. Many people use these terms interchangeably when talking about health benefits or supplementation.

Does glutamine build muscle?

Despite being an important part of muscle cells, glutamine is not considered a "building block" of muscle like other amino acids. However, it is important for proper muscle function and recovery.

What are the best sources of L-glutamine?

The best source for getting any vitamin or nutrient into your body is through your diet. Your body will process L-glutamine more efficiently from the foods you eat than it will from a supplement.

Meat and animal products are probably the easiest way to get high amounts of L-glutamine into your diet.

What is the recommended dose of L-Glutamine?

WebMD recommends doses of up to 40 grams per day for adults. For children, the recommended dose is up 0.7 grams/kg body weight daily.

Is L-Glutamine considered safe?

Yes, L-Glutamine is generally considered safe. Side effects are usually mild.


If you're looking to improve your immunity or gut health, L-glutamine may be a good option for you. It's found naturally in many foods and is generally considered safe.

Although it doesn't directly improve muscle growth or performance, making sure you get a good supply in your diet can help support overall wellness and health. Which is an important part of any training program.

As with any supplement, it's always best to talk to your doctor before starting anything new, especially if you have a medical condition.

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