9 L-Glutamine Benefits For Your Health & Its Sources

Reviewed by Madhu Sharma, RD, Registered Dietitian
Written by Ravi Teja Tadimalla, Professional Certificate In Food, Nutrition & Health

There are many benefits of L- glutamine, and athletes favor it a lot. When you spend your mornings at the gym, you don’t always see results in your muscles. If you feel fatigued in the afternoons after work or tired at night, you need a boost of amino acids to prevent lethargy. And taking L-glutamine may help.

A diet high in L-glutamine can help boost your gut and brain health and improve your fitness. This article discusses the benefits, potential side effects, and the best sources of L-glutamine. Keep reading.

Table of Contents

Why Are Amino Acids Important?

Glutamine is an amino acid. And it is available in two forms – L-glutamine and D-glutamine. Of the two, L-glutamine is most beneficial to humans and is naturally found in foods.

Before you get to know more about L-glutamine, it is important you know why amino acids are necessary.

We know that our body is made of proteins. And proteins are made of amino acids. These amino acids are vital for several bodily functions. Deficiency of amino acids can lead to an increased risk of disease, stress, anxiety, low energy levels, and several other complications. Now you know why they are important.

Amino acids are of two types – essential and non-essential. The former is the class of amino acids that our body cannot produce and must be taken from external sources. And the latter are those our body can produce. What makes L-glutamine unique (almost) is that it is a non-essential but conditionally essential amino acid – your body needs it only during times of injury or severe stress (1), (2).

What Makes L-Glutamine Unique?

There are 20 amino acids. But why are we talking about L-glutamine alone? What’s so special about it?

L-glutamine plays a special role in improving gut health. And why are we stressing about that? Because the gut is often called the body’s second brain. The health of your gastrointestinal system plays the most important role in your overall well-being. Though L-glutamine has other benefits, its role in boosting gut health is what sets it apart (3).

L-glutamine is the most abundant amino acid in the human body. Its concentration is higher than all the other 19 amino acids combined.

And like we said, it is a non-essential but conditionally essential amino acid. The body usually produces enough of it. But there are times when one needs to take the amino acid from external sources for its benefits.

What Are The Benefits Of L-Glutamine?

1. Improves Gastrointestinal Health

L-glutamine is crucial for repair and maintenance of the intestines, which is why it can work great for treating gastrointestinal issues like leaky gut and ulcerative colitis (4), (5). Studies also show how this amino acid can help preserve the gut barrier and protect the intestinal junctions from disease (6). And since issues like leaky gut also cause hypothyroidism and psoriasis, glutamine can help prevent these ailments as well.

Some studies also state that L-glutamine could be useful in the treatment of irritable bowel syndrome. However, research is still in its initial stages and promising data is lacking. More studies are warranted in this regard (7), (8).

Glutamine also fights intestinal inflammation and helps people recover fast from food sensitivities. It also boosts the activity of the immune system within the gut, further promoting gut health. It also acts as a source of energy for the intestinal cells.

2. Can Aid Weight Loss


Some research shows that glutamine intake could be a safe and effective way to aid weight loss (9). This could especially be true if your glutamine comes from foods rich in protein as well. Foods rich in protein can help you feel full for longer periods, and this could aid weight loss in a way (10).

However, we need more studies to understand the mechanism of glutamine in weight loss.

Interestingly, the levels of HGH (human growth hormone) are up by close to 400% post glutamine intake. This can offer great benefits as HGH is known to boost resting metabolism and after-burn effect (which is required for burning fat) (11). These effects also help build lean muscle mass and help in weight loss.

3. May Help Fight Cancer

In studies, L-glutamine had exhibited a preventive role against cancer. It had helped prevent cancer and its associated effects, in addition to restoring the intestinal mucosa (which also have a role to play in cancer prevention and treatment) (12).

4. Builds Muscle

Since L-glutamine is linked to protein synthesis, it protects your muscles from being catabolized (or eaten up). Also, glutamine levels are bound to diminish during intense workout sessions – which is where L-glutamine helps to make up for the lost glutamine.

And as we say, glutamine plays a role in the production of human growth hormone – which again contributes to muscle growth. The hormone increases the volume of muscle cells and increases muscle mass. In a way, it helps preserve muscle tissue.

Also, did you know that about 60% of your skeletal muscle is made of glutamine? That speaks a lot about the importance of glutamine for muscle building, doesn’t it?

5. Enhances Athletic Performance


We already saw how glutamine could prevent muscle catabolism and improve the levels of HGH – and these factors improve athletic performance as well. In addition, glutamine also enhances glycogen storage and hydrates muscle cells – and this further proves to be beneficial to athletes.

Another way glutamine helps is by ridding the body of excess levels of ammonia – as interesting as it might seem, this amino acid converts additional ammonia into beneficial amino acids, improving athletic performance as a result (13).

6. Boosts Immunity

When patients who underwent bone marrow transplantation were supplemented with glutamine, they showed a lowered risk of contracting infections – this does show the potential of L-glutamine as an immune-boosting agent (14).

7. Promotes Brain Health

Glutamate is an important neurotransmitter in the brain, and glutamine helps regulate the glutamate-glutamine cycle (which is an important brain function). A disruption in this cycle can lead to serious brain ailments like epilepsy, anxiety, stress, depression, and even alcohol addiction (15).

L-glutamine was also found to slow down brain aging. Though more research is being done in this aspect, this sure looks encouraging.

8. May Help Treat Sickle Cell Anemia

This is one condition where the red blood cells shrink in size and shape, resulting in severe anemia. Some sources suggest that supplementation with L-glutamine can help treat this condition (16). However, we need more research here. So, consult your doctor before using the amino acid for this purpose.

9. Can Aid Diabetes Treatment

We saw that L-glutamine helps burn fat. One of the other ways it achieves this is by suppressing insulin levels and stabilizing blood glucose levels. This way, it helps combat high blood sugar levels, thereby preventing diabetes (and even helping with diabetes treatment).

More interestingly, this amino acid helps fight sugar and carb cravings as well – thereby making it easier for individuals to prevent high blood sugar (17).

These are the ways L-glutamine can help make your life better. Well, the amino acid is already produced by your body. So, you don’t need to take it from external sources, unless in certain situations – these include injury or illness or extreme stress.

Talking about external sources, what foods are rich in this amino acid?

What Are The Richest Sources Of L-Glutamine?

Glutamine is available in plant and animal sources, though the amino acid from the animal sources is not as easily digestible. The sources of glutamine include:

  • Bone broth
  • Spirulina
  • Grass-fed beef
  • Eggs
  • Asparagus
  • Chinese cabbage
  • Broccoli rabe
  • Venison
  • Turkey
  • Wild salmon
  • Tofu
  • Corn
  • Skim milk

The dosage of L-glutamine is more important to be considered while taking supplements. The best dosage is 2 to 5 grams of the amino acid daily. For power athletes, this dosage can go up to 10 grams a day. But it is important to note that this dosage is for reference only, and we recommend you visit your doctor for the ideal dosage for you.

In case you are taking supplements for long-term benefits, you can also supplement with B vitamins (they prevent the build-up of glutamine in the body, which is rare). However, the use of glutamine supplements is not routinely recommended by medical professionals. We suggest you seek medical advice before going for any.

Though side effects with glutamine overdose are rare, you can check for these symptoms:

  • Hives
  • Breathing difficulties
  • Swelling of the lips, face, and tongue
  • Other serious side effects may include chest pain, hearing issues, and signs of fever like flu and weakness (visit your doctor right away in such cases).

L-glutamine is an important amino acid produced naturally in the body. This conditionally essential amino acid helps treat many ailments. L-glutamine benefits your health in many ways. For example, it may improve gastrointestinal health, aid in weight loss, help fight cancer, build muscle, and enhance athletic performance. It is available in many plant and animal sources. However, excess consumption of this amino acid may cause hives, breathing difficulties, swelling of lips, and chest pain. Hence, consume it in the recommended dosage. Consult your doctor in case of any emergencies.

Frequently Asked Questions

How long does L-glutamine take to help heal intestinal issues?

Most gut problems can take 2 to 12 weeks to heal. In case of more severe gut problems, glutamine can take anywhere between 12 to 24 months to show results.

Where to buy L-glutamine supplements?

You can buy the supplements from your nearest health store or online.


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Madhu Sharma

Madhu Sharma is a member of the National Executive Committee of IDA. She has been associated for almost three decades... more