The Comprehensive Guide to Glutamine

man and woman holding battle ropes

Most people in the health or fitness industry are familiar with glutamine, but what is it? What does it do? If you have these questions, or any others, this article will have answers for you. 

Glutamine is an amino acid with many important roles in the body. It also happens to be naturally produced in the body; however, you may benefit from supplementing extra in your diet. If you are unsure about supplementing this amino acid, this article will also have answers for you!

If you are looking to order a supplemental powder that has been tested for safety and is easy on the wallet- here is a great option!

What is Glutamine?

Glutamine is an amino acid (a building block of protein), that plays many critical roles in the body. It exists in two forms: L-glutamine and D-glutamine. These two forms are almost identical, but have slightly different molecular arrangement.

L-glutamine, also just referred to as glutamine, is the type found in food and supplements, and is used to make proteins and perform other functions within the body. It is important for the immune system and intestinal health

Plain white supplement powder
It is normally an unflavored, fine, white powder

It is the most abundant amino acid within bodily fluids. However, there are times when your body cannot produce as much as it needs. For this reason, it is considered a conditionally essential amino acid

Under conditions such as injury or illness your body does not keep up with its own needs for this amino acid, and it must then be consumed to meet those needs. It can be consumed either through diet or through glutamine supplements.

D-glutamine really serves no purpose in humans.

Where is it Found in Food?

This amino acid naturally occurs in many foods, and the average diet contains about 3-6 grams per day. The foods that have the highest amount are high in protein. Below are some foods with high glutamine content listed as the amount per 100 grams of protein in that food:

Eggs are a great source of glutamine!
Eggs are a great source of glutamine!
  • Eggs – 0.6 g
  • Beef – 1.2 g
  • Skim milk – 0.3 g
  • Tofu – 0.6 g
  • White rice – 0.3 g
  • Corn – 0.4 g

It’s worth noting that although some plant sources have a high percentage of this amino acid, the overall protein content is low, so a large amount of those foods would need to be consumed to get the amount listed. With that in mind, animal products are the easiest way to increase glutamine consumption through food. Virtually any food containing protein will contain some of this amino acid.

Need help tracking protein intake? This app helps!

Want to learn more about the different types of proteins? Check out this article!

What Does Glutamine do?

One of the most important functions of glutamine is its role in the immune system. Glutamine is a critical fuel source for white blood cells and certain intestinal cells.

The immune system
A primary role of this amino acid is immune system function

This is why consumption of this amino acid should be increased after injuries, burns, or surgeries. This is also why glutamine supplements are often prescribed after significant burns or surgeries to reduce recovery time and risk of infection.

In fact, if your diet does not contain enough glutamine, your immune system can become compromised.

If enough of this amino acid is unavailable in the body while it is recovering, your body will break down muscles to access more of it. No one wants to lose their hard-earned gains!

Glutamine and Health

The immune system benefits of this amino acid are related to its role in intestinal health.

The intestines are the largest portion of the immune system because of the many intestinal cells with immune functions and all of the bacteria in your intestines that impact immune health.

Glutamine is an important energy source for both intestinal and immune cells, and it helps maintain the barrier between the inside of your intestines and the rest of the body. 


Glutamine helps maintain the barrier between the inside of your intestine and the rest of your body, protecting against a leaky gut. This prevents harmful bacteria and toxins from getting into the rest of your body.

This amino acid is also essential for the growth and maintenance of the cells in the intestine. This means that it benefits your overall immune health by supporting intestinal cells.

Glutamine for Muscle Gain

Although glutamine does not cause muscle gain, it does decrease muscle soreness and help improve recovery after intense exercise. In fact, one study found that it reduced blood markers of fatigue during two hours of running.

muscle fatigue from running

It may also boost the immune function of athletes, decreasing days off, and in turn allowing for more training.

Dosage, Safety, and Side Effects

Because this amino acid is naturally produced in the body and found in many foods, there is no need to be concerned about consuming normal quantities of it.

Glutamine supplements range in dosage, but amounts ranging from 5 to 45 grams per day have been studied with no adverse side effects for use up to 6 weeks. However, 5 to 15 grams per day seems to be plenty. 

Some studies have raised concerns about the uptake of other amino acids if glutamine is consumed in high quantities for a long period of time. However, there is no definitive data yet.

If you plan on taking this amino acid as a supplement, you should start with 5 grams daily. As with any supplement, you must buy from a company that is well trusted. Look for companies that have their products tested by third-party labs for purity and label accuracy. If you aren’t sure where to start, UXO supplements offer a reasonably priced, high-quality powder. You can learn more about it and order it here.

If you have more questions just leave them in the comments below!

In 2013 I attended TVCC with my studies focusing on nutrition and biology. After leaving TVCC I pursued a career in inbound marketing and have worked in many different industries including health and fitness, firearms, coaching, and many more. I spent 6 years training for powerlifting and 6 years after training for a bodybuilding show in Idaho, which sadly did not come to fruition.

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