Glutamine is an amino acid – a building block for protein – that plays a role in several bodily functions. While there are two types of glutamine, l-glutamine is the form that plays the most significant role in our body’s functioning, and is the type found in supplement form (1). Though more studies are needed, some evidence suggests glutamine plays a key role in maintaining a healthy immune system and could positively impact gut health (2) (3) (4). Though claims of glutamine’s role in strength training are likely overblown, there is some potential indication that it may aid in post-workout recovery, though more research is needed to substantiate that claim (5) (6).

The human body produces glutamine and it is available in a variety of foods, so folks following a well-balanced diet are likely getting an adequate amount of this amino acid in their daily diet. However, glutamine is most commonly available in meat and animal products, and so folks following a vegan or vegetarian diet may consider a glutamine supplement to bolster their intake. It’s wise to consult a medical professional before introducing additional glutamine to your diet. With so many glutamine supplements available on the market, it’s important to know how to distinguish between all the options.

Best Glutamine

Editors’ Choice:

Optimum Nutrition L-Glutamine Powder

Pros:

  • On a per serving basis, Optimum Nutrition’s glutamine offering is very competitively priced. 
  • Each teaspoon-sized serving contains 5g of l-glutamine.
  • This amino acid powder is unflavored and easily mixes with a variety of drinks. 
  • With no other ingredients aside from l-glutamine, Optimum Nutrition’s powder receives top marks for purity from third party testing via Labdoor. 
  • Vegan-friendly.

Cons:

  • There’s no scoop included in the container, which may make measuring out your portions a bit inconvenient. 
Optimum Nutrition L-Glutamine Powder
Optimum Nutrition L-Glutamine Powder
Optimum Nutrition L-Glutamine Powder

With high purity scores from independent third party testing via Labdoor, Optimum Nutrition L-Glutamine Powder is an excellent choice for a powdered glutamine supplement. This unflavored powder mixes easily with most drinks and contains 5g of glutamine per teaspoon sized serving.

Contender:

NOW Sports Glutamine Powder

Pros:

  • According to third party testing via Labdoor, NOW Sports has very high marks for purity, safety, and nutritional value. 
  • Recommended serving size on the container is 5g
  • Vegan, soy-free, kosher
  • No other ingredients listed – just pure l-glutamine.
  • Touted as a post-workout recovery drink.

Cons:

  • Unfortunately, there’s no scoop included in the packaging. 
  • A few reviewers mentioned it can be a bit tricky to get the last few scoops from the bottom of the container.
NOW Sports Glutamine Powder
NOW Sports Glutamine Powder
NOW Sports Glutamine Powder

NOW Sports offers a very solid glutamine powder, highly ranked for purity, safety, and nutritional value via independent testing at Labdoor. Marketed as a post-workout recovery drink, this powder is vegan and kosher. 

Best Capsule:

NOW Supplements L-Glutamine

Pros:

  • NOW Supplements’ capsules are halal, non-GMO, kosher, and vegan/vegetarian.
  • Compared to other glutamine capsules on the market, NOW Supplements’ l-glutamine is competitively priced. 
  • These capsules are produced in a Good Manufacturing Practices facility.

Cons:

  • The suggested serving size is one 500mg capsule, much less than competing brands. If you’d like to get a higher dosage of l-glutamine, you’ll burn through the 120 capsule bottle pretty quickly. 
  • Contains rice flour.
NOW Supplements L-Glutamine
NOW Supplements L-Glutamine
NOW Supplements L-Glutamine

If mixing up a powder doesn’t work with your routine, you might consider getting your l-glutamine from a capsule. NOW Supplements offers a cost-friendly, vegan-friendly l-glutamine capsule. 

Contending Capsule:

Optimum Nutrition Glutamine Caps

Pros:

  • For folks with busy schedules or who are on the go, capsules may be more convenient than powders.
  • Each suggested serving is two 500mg capsules. 
  • According to third party testing via Labdoor, these capsules rate very highly for purity. 
  • On a cost per capsule basis, these are quite competitively priced as far as glutamine capsules are concerned. 

Cons:

  • Since these capsules are made with gelatin, they are not vegan friendly.
  • There is considerably less glutamine per serving than in powdered versions of l-glutamine.
Optimum Nutrition Glutamine Caps
Optimum Nutrition Glutamine Caps
Optimum Nutrition Glutamine Caps

With a high score for purity according to independent third party testing, Optimum Nutrition offers an excellent glutamine capsule. A drawback here, however, is that these caps are made with gelatin, meaning they are not conducive to a vegan diet. 

Also Consider:

BulkSupplements L-Glutamine Powder

Pros:

  • BulkSupplements L-Glutamine powder only has one ingredient: l-glutamine. 
  • Each package contains 500 one gram servings of l-glutamine powder.
  • BulkSupplements L-Glutamine Powder received high marks for purity on third party testing at Labdoor. 
  • Comes in a resealable bag that may take up less room in storage than bulkier tubs of competing powders. 

Cons:

  • There’s no scoop included, meaning you’ll need to measure accurately to ensure you’re getting a correct dosage of l-glutamine. 
  • While still competitively priced, this powder is a bit more expensive than some competing powders we looked at.
BulkSupplements L-Glutamine Powder
BulkSupplements L-Glutamine Powder
BulkSupplements L-Glutamine Powder

Made by a company that prides itself in simple supplements, BulkSupplements L-Glutamine Powder is another solid option for those seeking out an l-glutamine powder. There’s no additional ingredients in this non-GMO, third party tested supplement.

Methodology

L-Glutamine is a naturally occurring amino acid that plays a key role in helping the human body work effectively. Widely available via meat and animal products, folks following a vegan or vegetarian diet may choose to bolster their glutamine intake with a supplement. Though more research is needed, some evidence suggests that glutamine may be helpful as a post workout recovery supplement. Others turn to l-glutamine supplements to treat “leaky gut.” Regardless of what brings you to seek out l-glutamine, it’s important to consult with a medical professional before adding it to your regimen.

Purity

As with any supplement, you want to know what you’re putting into your body. Check for available third party testing for purity.

Ingredients

Take a look at the supplement’s label to ensure there are no extraneous or unwanted ingredients. Some manufacturers will include additives for texture or flavor.

Capsule vs. Powder

For some folks, this may come down to a matter of convenience. While powders allow you to be more accurate about how much of a supplement you’re ingesting, it may be cumbersome to mix up a drink on a regular basis. On the other hand, capsules are generally a bit more expensive on a per gram basis, but may be more convenient for folks who are on the go or dealing with an already jam-packed morning routine. 

Cost

Since the serving sizes can vary from product to product, divide the total cost by the amount of grams in each container to get a sense for the cost per gram. 

BarBend Tips

  • Start slow: if you’re introducing l-glutamine to your diet, it may be wise to start out with half-sized servings for a few days to let you body acclimate to the new supplement.
  • Check in with a medical professional before introducing l-glutamine to your diet

L-glutamine is a naturally occurring amino acid and a very popular supplement for a variety of reasons. Before loading up on the stuff, take into account how and when you intend to use it, and consult with a medical professional.

References

  1. Hall JC, Heel K, McCauley R. Glutamine. The British journal of surgery. 1996;83(3):305-312.
  2. Demling RH. Nutrition, anabolism, and the wound healing process: an overview. Eplasty. 2009;9:e9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2642618/.‌
  3. Calder PC, Yaqoob P. Glutamine and the immune system. Amino acids. 1999;17(3):227-241. https://www.ncbi.nlm.nih.gov/pubmed/10582122.
  4. Krishna Rao R. Role of Glutamine in Protection of Intestinal Epithelial Tight Junctions. Journal of Epithelial Biology and Pharmacology. 2012;5(1):47-54.
  5. ‌Legault Z, Bagnall N, Kimmerly DS. 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 metabolism. 2015;25(5):417-426.
  6. ‌English N. Is a Glutamine Supplement Actually Worth Your Money? BarBend. https://barbend.com/glutamine-supplements/. Published March 22, 2017.