L-glutamine is an amino acid that has grown immensely in popularity within the supplement industry recently. The only problem is that finding the best l glutamine powder can be difficult, if you do not know what to look for. In this best l glutamine powder review, we will review the best options for glutamine based on your specific needs.

The 6 Best L Glutamine Powders

Best Overall: Naked Nutrition Pure L-Glutamine Powder

Best for Vegans: Naked Nutrition Pure L-Glutamine Powder

Best for Capsules: Optimum Nutrition L-Glutamine Capsules & Pure Encapsulation L-Glutamine

Best for Budget: BulkSupplements L-Glutamine Powder

Best for Flavors: Transparent Labs BCAA Glutamine Intra-Workout Powder

What is Glutamine? 

Glutamine is considered a conditionally essential amino acid in your body. An amino acid is a molecule that serves as a building block of protein within your body.

It is actually the amino acid most abundantly found in your body. It is necessary for the production of both protein, glucose, and other amino acids within your body.

Like a lot of other amino acids, glutamine comes in other forms, with it coming in: D-Glutamine and L-Glutamine. Both of these forms vary in molecular structures, but are largely the same substance. 

Glutamine can be supplemented for many reasons from: building muscle, gut health, immune system health, recovery after surgery, and many others.

best l glutamine powder picture 1


Immune System Support

The main role of glutamine in your body is aiding your immune system. It is used as a fuel source for your immune cells, which consist of some intestinal cells and your white blood cells.

After major injuries, surgeries, or even burns, when your body is in a state of recovery and your blood levels may be decreased, your body is in need of glutamine.

If your body isn’t sufficiently receiving enough glutamine from your diet, then your body will break down your protein cells to receive more glutamine.

By supplementing with glutamine during these periods, you can aid your body in its recovery and prevent the breakdown of protein cells for additional glutamine.

Glutamine supplementation has been shown to improve health, decrease infection risk, and shorten post-surgery hospital stays.

Glutamine supplementation has also shown improved immune function within animals fighting off bacterial and viral infections. Despite the evidence that show benefits in animal immune systems, there is no convincing evidence that additional glutamine supplementation on top of your daily diet shows any benefits in immune support function in healthy adults.

Intestinal Health

In addition to the benefits that glutamine shows in immune system support, it also helps to support your intestinal health.

Despite common confusion, your intestines are actually considered part of your immune system and not your digestive system. In addition to them being considered a part of your immune system, they are also the largest portion of your immune system.

The cells within your intestine, intestinal cells, are responsible for immune functions, in addition to the trillions of bacteria within your intestinal biome that impact your immune health.

Glutamine benefits your intestinal health because it is used as the crucial energy source for these cells.

These cells have the responsibility of tasks, such as maintaining the barrier between the inside of your intestines and your body. The circumstance when these cells fail in this task is known as “leaky gut” and a possible reason for this is because your cells are not receiving enough glutamine for energy. Your intestines would also not be able to prevent harmful bacteria from traveling to your body or even maintaining and growing new cells within your intestine.  

Muscle Growth and Performance

Glutamine has become a popular supplement within the fitness industry recently, due to its perceived benefits for muscle growth and protein synthesis.

There have been many studies that have researched to see if it did indeed present a benefit in this regard.

The first study monitored a group of 31 patients, split into 2 groups with one supplementing glutamine and the other with a placebo, over 6 weeks of the same weight training schedule.

At the end of the sixth week, there was no difference in the gained muscle mass and strength between both groups. They both gained muscle mass, but at the same rate. There have been several other studies to prove the same result, such as the ones found here and here.

There has been some studies to show glutamine supplementation led to a reduced fatigue after 2 hours of running, but there has been additional research to show that there was no improvement in recovery of glycogen stores within muscles after exercise with supplementation.

Overall, there has no been no evidence to suggest a benefit towards building muscle mass or strength with the supplementation of glutamine, in either form. There has been brief research that show a improved recovery, but not enough to make a definite decision.

If your goal is to build muscle mass and increase your strength, your main priority should be to consume a high protein diet, which will in turn provide your body with plenty of glutamine.

Forms of Glutamine


This is the most common form of the amino acid, glutamine. It is the form of glutamine that is naturally found and produced within your body. It is the most abundantly found amino acid within your body. You will find this form of glutamine within most of the glutamine supplements currently found on the market.

N-Acetyl L-Glutamine

The N-Acetyl form of L-Glutamine is just normal l-glutamine combined with acetic acid. This gives it the N-Acetyl name and is a more easily digested form of L-Glutamine. There is some research that suggests that there is a difference in the absorption by the intestines between the 2 forms. This leads people who are supplementing glutamine for gut health to be more attracted to this form of L-Glutamine.


Although D-Glutamine is nearly the same substance as L-Glutamine, it contains a slight difference in their molecular structure. Although this form of glutamine is found within your body as a non essential amino acid, it doesn’t contain much responsibility in aiding your bodily functions. This form of glutamine is never found in glutamine supplements and would provide no benefit in supplementing over the other forms available.

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Forms of Glutamine Supplementation


Glutamine should be supplemented in the powdered form, if you are looking for the most cost efficient and effective form of supplementation. Consuming powdered glutamine will almost always be the most wallet friendly option in comparison to supplementing with capsules. Depending on your preference, it is also rather simple to supplement with, in most cases, one scoop into a beverage and you are done for the day. Powdered glutamine usually comes in unflavored versions to make it easy to mix with anything, but it can occasionally be bought in a flavored version.


The main benefit of supplementing with capsules over the powdered version of glutamine is if you are looking for a more travel friendly option. In the long run it will cost more than powdered and you will have to take a lot of capsules to reach your daily supplementation, but it is a lot easier to travel with.

Also check to make sure before buying a capsuled version, that you are not consuming any unnecessary ingredients in the product.

Side Effects

Glutamine is the most common amino acid within your body, so supplementing in normal doses is usually not harmful.

Short term supplementation is widely regarded as safe, but as a long term addition to your supplement regime there have been concerns raised about its safety. 

Generally, there is not a lot of information regarding the long term supplementation of glutamine on your body. Therefore, for the short term, glutamine can be a great addition, but for long term purposes, it might be best to look into ways to naturally implement more into your daily diet.

When to Take Glutamine

Glutamine is an amino acid that can be supplemented at any time of the day. You can time your supplementation at certain times depending on your needs, such as post-workout to help with muscle recovery or pre-workout to help battle fatigue.

If you are supplementing glutamine for any reason other than for athletic performance, then it comes down to preference on what time during the day you take it.

Daily Supplementation & Dosage

Daily supplementation of glutamine of any form is generally considered to be safe. The amount you should supplement every day depends on a couple of factors, however. First, the amount of glutamine you need for supplementation depends on your body weight. It is generally considered to be around 0.2g to 0.4g per kilogram of bodyweight. Another factor is your diet, a typical diet contains around 3-6g of glutamine, so if you have a diet that is insufficient or vice versa , you should supplement more.

Generally, supplementing 5g to 15g of glutamine per day is considered to be the safest area. Most supplements will come with a serving size of 5g, so it is suggested to start there and if needed, work up the dosages to the maximum.

Just to keep in mind, if you are going to supplement with a higher range of glutamine, then you might also want to consider supplementing with vitamin B12. Vitamin B12 helps control and regulate the buildup of glutamine within your body.

How Long to Take Effect

Depending on your need for supplementing glutamine, the amount of time it takes to take effect can range. If you are taking glutamine to help with muscle fatigue and recovery, then you should start to notice a difference after one day and then more of an affect after continuous use.

For the intestinal benefits or for aiding leaky gut, then it really comes down to the individual. It depends on your diet, the quality of the supplement, and any chronic underlying causes.

What to Consider Before Buying

We had several factors in choosing our best glutamine supplements in this review, that you should also consider. For this reason, we included 6 of the best l glutamine powders based on specific needs.

Ingredients and Brand

When choosing supplements for any of our reviews, our first priority is making sure the product is safe to consume and from a reputable company with good practices. We would never include a product that is from a non-reputable company or could have ingredients that are not safe or not disclosed.

In this review, our main focus was to make sure that L-Glutamine or N-Acetyl L-Glutamine was the only ingredient included. Some exceptions were made for the flavored options and the encapsulated option, but the rest contain pure powdered glutamine.

We also made sure that every product included was from a strong and reputable brand. The brands recommended have been around for a long time with good business practices and have a strong customer base.

We also considered certifications from other third party sources, such as being certified gluten free or certified vegan.


The next factor included in our review was the cost of the product. The individual product are going to be largely all the same, so once we found the products with the best ingredients and brand, we considered the cost of each. For the most part, there is no reason to include a product that is double the price per serving than another.

There are many factors in considering cost, however, such as brand popularity, servings, quality, and others.


Finally, we considered the form of glutamine. The most common form of glutamine supplementation is through the powdered form due to the cost effectiveness of the substance.

For this reason, we only included one selection on the list in the capsulated form. When considering the capsulated form, we made sure to find the highest serving size to hit your daily needs, while still not compromising on the quality.

If you are vegan and looking for the capsulated version, be careful to keep an eye out for the inclusion of gelatin in the ingredient list. For this reason, we included a vegan and non-vegan product in our top pick for the capsules category.

Is it Safe?

Glutamine supplementation in any form, is generally considered safe in the short term. 

You should still be aware that some may be allergic to glutamine or even to some of the small dosed ingredients in the supplement. If this is the case, you should stop supplementation immediately and consult with your primary care physician.

Glutamine supplementation is generally considered to not cause any side effects, but if you do start to experience any mild side effects, such as nausea or bloating, then you should reassess your dosage or stop supplementation all together.

In terms of long term supplementation of glutamine, not much is known in regards to its safety. This is not to say it is unsafe, but rather that there have not been enough studies conducted to make a definitive claim. If you plan to supplement glutamine over the long term, I would suggest staying in touch with recent studies and findings in regards to new side effects or the lack thereof.

6 Best L Glutamine Powders

Below are the best l glutamine powders for their specific categories.

Best Overall – Naked Nutrition Pure L-Glutamine

The Naked Nutrition L-Glutamine perfectly encompasses everything to look for in a glutamine supplement. To start off, the brand is completely centered around providing supplements with the cleanest ingredients and with minimal unnecessary ingredients.

They use a pure l-glutamine with a serving size of 5g, which is a standard serving size. The supplement comes with 200 servings as well, for a total of 1000g of glutamine. It is also certified vegan, certified gluten free, and made in the USA.

Key Features
  • Certified Gluten Free and Vegan
  • Pure L-Glutamine
  • Powdered
  • Clean Ingredient Profile
  • Reputable Brand
  • Certifications
  • Not as affordable as other options on the list
  • No options for flavoring, if wanted
Buy on Amazon Buy on Naked Nutrition

Best Vegan – Naked Nutrition Pure L-Glutamine

In addition to also being the best overall option, Naked Nutrition’s L-Glutamine was also the best vegan option for glutamine in the powdered form. This again comes down to the company’s business model of providing the cleanest and minimal supplements on the market.

They provide pure l-glutamine, while being certified vegan, in addition to many other great factors. The reason their glutamine is vegan is because their glutamine is 100% naturally fermented from plant sources.

Key Features:
  • Certified Vegan
  • Clean Ingredients
  • Plant Derived L-Glutamine
  • Certified Vegan
  • Clean Ingredient Profile
  • Strong Brand Profile
  • Not the most affordable option
  • Only comes in unflavored
Buy on Amazon Buy on Naked Nutrition

Best Capsules – Optimum Nutrition L-Glutamine Capsules & Pure Encapsulation L-Glutamine Capsules

We very rarely include joint winners for the winner of a category, but based on the product we decided to include our best capsules pick and our best allergen friendly capsule pick.

To start off with our best capsule pick, Optimum Nutrition L-Glutamine capsules rose above the other options for many reasons. To start off, unless you were just introduced to the fitness industry, you have heard of Optimum Nutrition. They have been a staple brand in the supplement industry for a long time and they have built a strong reputation and loyal customer base in the process.

Another reason, why they were chosen over other options was because they only contain gelatin and magnesium stearate. This is a good amount of ingredients for the capsulated version of l-glutamine, while other options might have 2-3 more ingredients in their capsules.

On the other hand, the capsules only contain around 500mg per, but this is normal for l-glutamine capsules. In addition, due to recent popularity around the company, most of their products have skyrocketed in prices over the last couple of years. Depending on when you buy them, they might not be the best deal.

Key Features:
  • Reputable Brand
  • Minimal Ingredients
  • Reputable Brand
  • Minimal Ingredients
  • Small Serving Dosage
  • More expensive, due to recent popularity
Buy on Amazon

Best Allergen Friendly Capsules – Pure encapsulation L-Glutamine Capsules

Now onto the best allergen friendly l glutamine capsules with Pure Encapsulation L-Glutamine Capsules. Pure Encapsulation won the category for the best allergen friendly l glutamine capsules because they are certified gluten free, in addition to vegan, soy free, dairy free, GMO free, and vegetarian. They also do not contain magnesium stearate, in compassion to their counterpart in this category.

They are largely allergen free and are a clean company, who also make their supplements in the USA. This capsule also provides l-glutamine in the free form. Just to keep in mind, free form l-glutamine should be taken with food.

Key Features:
  • Free form L-Glutamine
  • Certified Gluten Free & Others
  • Made in USA
  • Only One Ingredient, L-Glutamine
  • Trustworthy Company
  • More expensive than other capsule options
  • 500mg serving size
Buy on Amazon

Best For Bulk L-Glutamine – BulkSupplements Glutamine Powder

BulkSupplement Glutamine Powder was the clear winner in regards to buying l-glutamine in bulk. They offer sizes from 3.53 ounces to 2.2 pounds, with the largest coming with 1000 servings of of L-Glutamine.

It is also free of allergens and only contains l-glutamine. It comes in only unflavored powder.

Key Features:
  • Bulk Options
  • Allergen Free
  • Up to 2.2 pounds options
  • Allergen Free
  • One Ingredient
  • No certifications
  • No information regarding quality
Buy on Amazon

Best For Flavors – Transparent Labs BCAA Glutamine Intra Workout

best l glutamine powder review - transparent labs bcaa and glutamine

There are not many supplement brands currently offering l-glutamine with flavors, but the highest quality option available is Transparent Labs BCAA and Glutamine Intra Workout. If you are looking for a pure l-glutamine option, this wouldn’t be your best option because it contains BCAAs and Coconut Water Powder.

On the other hand, if you don’t mind the additional fermented vegan BCAAs of L-Leucine, L-Isoleucine, and L-Valine with Coconut Water Powder, then this is a great option. The glutamine and BCAAs with help with muscle recovery and growth, while the coconut water powder will help keep you hydrated during your workout.

It comes in blue raspberry, sour green apple, tropical punch, strawberry lemonade, and orange.

Key Features:
  • 5 Flavors
  • No Artificial Sweeteners, Coloring, or Preservatives
  • 5g of L-Glutamine with BCAAs and Coconut Water Powder
  • Additional Ingredients that make an efficient Intra-Workout option
  • 5 Flavors (I’m a fan of the classic blue raspberry)
  • No Artificial Additives
  • Not pure l-glutamine
  • Large list of ingredients
  • Much more expensive option than others
Buy on Transparent Labs


Powder vs. Capsules?

Whether you should supplement l-glutamine using a powder or a capsuled option comes down to personal preference. Are you willing to pay the extra money for the convenience of the travel friendly capsules? If not, the powder is the way to go.

The capsule version requires a large amount of capsules to be consumed for the recommended serving size, which could be detrimental to your wallet over a sustained period of time.

Should I Supplement Glutamine?

L-glutamine should be supplemented when you are not able to achieve it within your daily diet. Cases such as certain diseases, injuries, and other conditions require more l-glutamine for your body to recover effectively.

A list of these conditions are:

  • Surgery
  • Sickle Cell
  • Burns
  • Gut/Intestinal Problems
  • Immune Problems
  • Injuries
  • Diarrhea
  • Cystic Fibrosis
  • Obesity
  • Lung Cancer

The list for circumstances when your body would supplement from additional supplementation is long, but these are some of the most common.

If you do not have any underlying condition, it might be best to try and achieve your daily needs for glutamine within your diet and then supplementing if you cannot.

Does it Help Build Muscle?

There has been no definitive research to prove that l-glutamine really does help build muscle, but there is some research to suggest that it could help with muscle fatigue and muscle recovery post-workout.

How Much is Too Much Glutamine?

It is generally considered for a range of l-glutamine of 5-15g daily for supplementation to be safe. This varies by your individual needs and your diet, but you should start off at 5g and slowly increase to a maximum of 15g, if desired results are not occurring.

Foods High in Glutamine

Foods that are high in glutamine are most protein dense options, such as:

  • Beef
  • Chicken
  • Fish
  • Eggs
  • Milk
  • Tofu
  • White Rice
  • Legumes
  • Vegetables (cabbage, corn, beets, spinach)

Does it Help with Leaky Gut?

Although there is no definitive conclusion on whether glutamine supplementation can help with leaky gut, there is evidence from some studies that showed that some patients who supplemented glutamine in their diet improved better in terms of intestinal permeability, in comparison to the other group.


L-Glutamine is the most abundant amino acid in the human body and for good reason. It is a major factor in our immune system health. In certain circumstances, supplementation of this amino acid may be necessary for your immune system. We went over the 5 best l glutamine powder and capsule options based on categories of the best, vegan, capsules, budget, and flavors. These were chosen through strict criteria and hands on testing of the products. 


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