4 Benefits of L-Glutamine & How To Supplement With It

L-Glutamine is one of the 20 amino acids in dietary protein and is considered a conditionally essential amino acid, meaning that it’s only considered an essential amino acid in some situations (during critical disease or physical trauma)

It is the most common amino acid (aka. protein building blocks) found in the body. You’ve probably only seen it in the supplement stores where it’s advertised towards athletes as it’s usually a staple supplement in most bodybuilders diets because of it’s great ability to repair muscle tissue. However, if you look into the research it only seems to have benefits the as supplementation when the body is deficient because of dietary restraints (veganism and non-dairy vegetarianism), during critical disease or long, intense cardiovascular exercise.

What the science says about L-Glutamine:

• Increasing Lean Mass:
  Glutamine is used in the biosynthesis of protein which is why it’s been linked to helping in building and repairing muscle and preventing muscle breakdown. However, this theory has not been supported by studies on healthy individuals (1).
• Support The Immune System:
  Glutamine is the main energy source for leukocytes, the immune cells, and contributes to the regeneration of these cells. Usually, the Glutamine levels in the body are well within the ideal range for optimal leukocyte growth, but supplementation to improve immune function can be beneficial in the case of intense physical stress (ie. critical illness or prolonged cardiovascular exercise). A study on children with diarrhea (1) showed no improvement of immune function.
• Digestive Health:
  Research shows that L-Glutamine supplements might have an effect on chronic bowel diseases such as Crohn’s Disease (1, 2, 3) and Ulcerative Colitis (1). However, the results are unreliable and more research needs to be done to prove a significant effect.
• Reduction Of Ammonia
  Ammonia is a by-product of amino acid breakdown. Its reduction may increase endurance and cognitive function during long-duration cardiovascular exercise. Supplementation with Glutamine seems to significantly decrease ammonium levels (1, 2, 3)

How to supplement with L-Glutamine:

If you do long duration cardiovascular exercise or have digestive issues, it might be a good idea to supplement with L-Glutamine.
It can be discussed if it could also be beneficial to supplement with Glutamine if you do long and intense workouts with weights (bodybuilding.
It is sold as an isolated amino acid in form of a dietary supplement but also naturally found in high doses in (organic) meat, bone broth, eggs, whey- and casein protein. If you’re looking for a natural, plant-based source you can look to red cabbage.

Glutamine supplements usually come in a powder form that can be mixed with water, protein powder or other liquids. You can also find it in tablet form.
It’s basically tasteless and I personally prefer to take 2 g. in my water in the morning as well as 2 g. in my post workout protein shake.
The best times to take L-Glutamine is generally in the morning, after your workout and/or before bedtime.
The exact optimal dose is unknown due to the low effect on increased muscle mass, but up to about 0,75 g./kilo body mass is very safe with no significant side effects. That’s around 60 g./day for an 80 kg. individual. I usually recommend supplementing with 2-6 g/day (depending on body mass) over 1-3 times and I recommend taking it in the form of powder as it can be easier to absorb than capsules. Especially if you’re taking glutamine to improve your digestive health.

Disclaimer: This post is not meant to diagnose or treat illness, and it is not meant to replace advice from your doctor. Always speak with your physician first before beginning any new supplements!