Glutamine is an amino acid produced by the body. It is an ingredient found in many supplements for different purposes. It has many benefits as well as possible side effects in some cases. The focus of this article is the L-glutamine form and its variety of benefits and functions.

What Is Glutamine?

Definition Glutamine

The body produces an abundant amount of amino acid called Glutamine. It affects the growth and functions of the cells found in the stomach. [1] Its primary purpose is to act as a building block for the proteins in the body. It aids the creation of other amino acids in the body.

Glutamine has two different forms, which are: D-glutamine and L-glutamine. Their molecular arrangements are different from one another. [2] L-glutamine is prevalent in foods and supplements for its multitude of benefits.

The substance is mainly found in the lungs and skeletal muscles. Glutamine performs essential functions that keep the body healthy. Supplements and different types of foods contain the substance as well.

L-Glutamine Benefits

L-Glutamine Benefits

This specific form of glutamine is considered an essential amino acid produced naturally by the body. Sometimes the need for L-glutamine by the body is greater than what it can produce. Hence, it must be acquired through other means to help you during certain situations or illnesses.

Here are some of the biggest benefits of L-glutamine:

1. Improve Immune System Functions

It plays a very vital role in the immune system of the body. The body uses it to fuel immune cells, such as white blood cells. [3] Insufficient L-glutamine in the body can compromise the immune system and its functions. If your body is not producing enough, it is recommended to consume it through a high-protein, high-glutamine diet or supplements.

A study was found on how glutamine supplements can aid in treating major injuries such as burns in the body. [4] The supplements can also help reduce risks or complications for patients in critical conditions. Having enough glutamine in the body helps reduce infections after surgeries as well.

2. Improve Intestinal Health

L-glutamine is a vital factor in keeping a healthy digestive tract due to its ability to maintain the health and integrity of the intestinal wall. It aids in repairing broken or damaged tissues, most especially in the digestive tract.

Glutamine is a vital source of energy for the immune and intestinal cells. [5] In addition, it acts as a barrier to prevent a leaky gut. This can prevent bacteria and toxins from spreading to the rest of the body. Moreover, glutamine aids in maintaining the proper growth of intestinal cells.

3. Exercise Performance/Muscle Gain

Several studies were conducted to examine the impact of glutamine on muscle building. So far, there is no significant evidence that glutamine affects muscle gain or fat burn. Researchers are continuing to study how glutamine supplements can muscle gaining.

However, some studies concluded that glutamine supplements can reduce soreness and fatigue. [6] Furthermore, they can improve the recovery of your body after intense exercise. Other studies have looked into the effects on athletes, however, results vary, and no conclusive data has been found.

4. Improve Skin Health

Amino acids, like glutamine, have a lot of benefits for the skin. L-glutamine helps in making the skin look smooth and radiant. The substance stimulates collagen production as well, which helps maintain skin elasticity. An increase in collagen production aids in smoothing out the wrinkles and retaining your natural skin tone.

L-glutamine, along with other amino acids, speeds up the healing process during breakouts. Your skin can heal faster than normal and help avoid long-term skin scarring. It’s a great substance to keep your skin looking more youthful and glowing.

5. Help In Weight Loss

Studies were conducted to know the correlation between L-glutamine and weight loss. One study found that the substance can be an effective way to aid in weight loss. [7] Foods rich in glutamine and protein are great to include in your daily diet. You will feel fuller for longer periods, so you will be better able to control how much you consume.

L-Glutamine Side Effects

In normal amounts, glutamine does not negatively affect the body as it is produced naturally. However, some people might experience side effects. Consult your doctor if necessary to avoid potential consequences.

A high intake of glutamine supplements may put the body through some side effects. If done for a long time, the way the body uses and distributes other amino acids might change. More studies need to be conducted to determine the effects of long-lasting high glutamine intake. For now, it is better to be a bit more cautious when it comes to how much dosage you want to take. Remember, aside from glutamine being produced by the body, it is also found in numerous food items. 

The side effects reported are mild such as nausea, stomach pain, and dizziness. Those who have cancer or are at risk are advised to avoid excess substance intake. Certain tumor cells can feed off glutamine and multiply faster.

Supplements containing glutamine are also not recommended for people with liver and kidney disease. It has been reported that an increased risk of brain function issues may arise. It is better to consult your doctor before taking any additional glutamine products.

Foods With L-Glutamine

Glutamine Foods

Several food items contain the substance and are important to include in your diet. Your daily activities reduce the glutamine produced by your body. Hence, it must be replaced by the food you eat. 

Here are some foods you can eat to balance out the glutamine content in your body:

  1. Meat

Meat is one of the richest sources of glutamine as it is high in protein. Beef, lamb, and chicken are great choices to include in your diet. For instance, roast chicken alone contains around 5.5g of the substance per 128g portion.

  1. Seafood

If you’re into baked salmon or fish curry, then you’re on the right track. Sardines, lobster, salmon, and many more are great sources of glutamine. Saltwater fish contains a higher amount of the substance than freshwater fish.

  1. Dairy

Dairy products such as cheese, yogurt, and other products made from milk are great sources of glutamine. It is the most prominent amino acid in milk protein, so it’s great to keep your glutamine level stable.

  1. Eggs

Including eggs in your daily diet is ideal, especially if you’re physically active. Aside from getting your glutamine fix, eggs are also rich in B vitamins, vitamin D, and vitamin K.

  1. Cabbage

Cabbage, especially red cabbage, is one of the healthiest foods available. It contains a high content of glutamine and other vitamins. To not diminish its vitamins, it’s better to eat cabbage raw in salads, sales, or sandwiches.

More foods can help balance your glutamine levels, such as nuts, seeds, and soya. Keep in mind that even though the aforementioned are healthy, eat everything in moderation.

Best L-Glutamine Supplements

L-Glutamine Supplements

Glutamine supplements come in multiple forms, such as capsules and powders. Remember, if you are not sure, consult a doctor to know about the right dosage to take. An excess of glutamine in your body may put you at risk, especially if you’re taking other medications.

  1. Now Foods Supplements

There are 120 capsules in each container, making it suitable for bulk purchases or people on a budget. The capsules contain plant-based cellulose and no gelatin. This is great for vegans, vegetarians, and those who want halal products.

  1. BulkSupplements L-Glutamine

You can mix this powder supplement with your water or workout drinks. The product does not have soy, sugar, dairy, additives, or gluten. It’s great for maintaining or improving endurance.

  1. Transparent Labs BCAA Glutamine

Each serving of this glutamine supplement contains other amino acids like BCAA to maximize the benefits. Its purpose is to increase muscle mass and reduce fatigue after training. It also has coconut water and vitamin C, albeit in small amounts. Different flavors for this specific product are available as well.

Bottomline: Glutamine Benefits And Side Effects

Glutamine is an amino acid produced naturally by the body. It has two forms, but L-glutamine is the most common and most effective. The substance provides many benefits, such as improving skin health, aiding in weight loss, and boosting gut health.

You can include several glutamine-rich foods in your daily diet as advised. Supplements in the form of capsules and powders are available for consumption as well. The foods and supplements help maintain great glutamine levels in the body. However, too much of the substance can pose risks and side effects. You can consult your doctor if needed.

Disclaimer: This article is only a guide. It does not substitute the advice given by your own healthcare professional. Before making any health-related decision, consult your healthcare professional.

Editorial References And Fact-Checking

  • University Of Michigan Health. (2014). glutamine | Michigan Medicine. Retrieved August 22, 2022, from
  • Durani S. (2008). Protein design with L- and D-alpha-amino acid structures as the alphabet. Accounts of chemical research41(10), 1301–1308.
  • Demling R. H. (2009). Nutrition, anabolism, and the wound healing process: an overview. Eplasty9, e9.
  • Kim H. (2011). Glutamine as an immunonutrient. Yonsei medical journal52(6), 892–897.
  • Legault, Z., Bagnall, N., & Kimmerly, D. S. (2015). The Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric Exercise. International journal of sport nutrition and exercise metabolism25(5), 417–426.
  • Laviano, A., Molfino, A., Lacaria, M. T., Canelli, A., De Leo, S., Preziosa, I., & Rossi Fanelli, F. (2014). Glutamine supplementation favors weight loss in nondieting obese female patients. A pilot study. European journal of clinical nutrition68(11), 1264–1266.


  • Beatriz Galang

    Beatriz is an exceptional freelance medical writer. This is a craft she has been honing since her university years. Beatriz also has experience writing content in the health and wellness field, which she is extremely passionate about. She aims to help her readers understand their health and wellness deeper and make better health-related decisions. LinkedIn


Beatriz is an exceptional freelance medical writer. This is a craft she has been honing since her university years. Beatriz also has experience writing content in the health and wellness field, which she is extremely passionate about. She aims to help her readers understand their health and wellness deeper and make better health-related decisions. LinkedIn