Ingredient Spotlight: L-Glutamine

Glutamine is one of the 20 amino acids that act as building blocks of protein. It’s made by your body except in times of stress. No doubt your hard workouts are an intense form of physical stress. That’s when it needs to come from your diet and 5% Nutrition supplements. In this edition of Ingredient Spotlight: L-Glutamine, we’ll take a close look at the function and benefits of this important amino acid. Plus, we’ll check out the 5% Nutrition products that contain l-glutamine. 

What Is L-Glutamine?

L-Glutamine is a conditionally essential amino acid that makes up 61% of skeletal muscle tissue. For that reason, it’s known as the most dominant amino acid found in the muscles. In addition, glutamine consists of 19% nitrogen, making it the main transporter of nitrogen into your muscle cells. Nitrogen is a primary component of your body. It’s required for both protein synthesis and the production of several nitrogenous compounds involved in many functions in the body. These include hormonal, neurotransmitter, and immune system functions, as well as antioxidant defenses.(1,2)

What Does L-Glutamine Do?

As noted, your body’s glutamine requirements increase during intense workouts or other times of stress, such as a pre-contest diet or injury. Also, it helps prevent muscle protein breakdown and supports recovery. Plus, glutamine affects BCAA metabolism and is involved in protein synthesis and glucose formation. Finally, immune system cells use glutamine as a primary fuel source. This is the main reason the requirements for glutamine increase when the immune system is stressed. (3,4,5,6)

What Is The Accepted Dose Of L-Glutamine?

The suggested dose is 5 grams. You can stack it with pretty much anything, and there is no need to cycle it.(7)

The 5% Nutrition Products That Contain L-Glutamine

Core L-Glutamine 5000

This is not just another “Core” product. Besides a 5-gram dose of glutamine, there are a couple of supporting ingredients - l-alanine and n-acetyl l-glutamine. Adding additional ingredients sets the 5% Core line apart from everybody else. Plus, it enhances the effectiveness of the primary ingredient, in this case, l-glutamine.

All Day You May

As an amino acid, you’ll find glutamine in our legendary All Day You May leucine-heavy amino acid powder. Don’t forget Stick Packs, the exclusive Maui Twist flavor, or All Day You May Caffeinated. Each one of these amazing and delicious amino formulas contains glutamine as part of a unique Conditionally Essential Amino Acid Blend.

The 5% Proteins

Shake Time, Real Carbs + Protein, and Snack Time are all sources of complete protein, and that includes all the amino acids, including glutamine. 


As we have seen, l-glutamine supports protein synthesis, helps prevent muscle protein breakdown from hard training, promotes improved recovery, and has a primary role in immune system health. Adding l-glutamine to your 5% Nutrition supplement arsenal can make a big difference in your progress. Stop and shop for it today!

  1. Hall, J C et al.; “Glutamine.”; The British Journal of Surgery vol. 83,3 (1996): 305-12. doi:10.1002/bjs.1800830306;
  3. Candow, D G et al.; “Effect of glutamine supplementation combined with resistance training in young adults.” European Journal of Applied Physiology vol. 86,2 (2001): 142-9. doi:10.1007/s00421-001-0523-y;
  4. Legault, Zachary et al.; “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 vol. 25,5 (2015): 417-26. doi:10.1123/ijsnem.2014-0209;
  5. Street, B. et al.; “Glutamine Supplementation in Recovery From Eccentric Exercise Attenuates Strength Loss and Muscle Soreness”; Journal of Exercise & Fitness; vol. 9,2 (2011): 116-122; (
  6. Calder, P C, and P Yaqoob.; “Glutamine and the immune system.”; Amino acids vol. 17,3 (1999): 227-41. doi:10.1007/BF01366922;
  7. Glutamine benefits, dosage and side effects - Evidence-based studies (
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