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Glutamine May Not Reduce Fatigue (Here's Why)

Updated: Aug 10

Evidence-Based. Scientifically Reviewed.

Glutamine is an extensively utilised conditionally necessary amino acid in sports nutrition, typically marketed for enhanced performance and muscle growth. It's also studied for it's effect on the immune system.

This amino acid serves a variety of other biological roles, including cell proliferation, energy synthesis, glycogenesis, ammonia buffering, and many other processes.

As a result, glutamine started to be studied in sports nutrition outside its immune system effects, with diverse qualities such as anti-fatigue being attributed to glutamine.

Does Glutamine Actually Work?

Because the ergogenic potential of this amino acid is still unknown, the goal of one review was to look at the main mechanisms by which glutamine works.

They primarily looked at how glutamine can delay fatigue, as well as the effects of glutamine supplementation, alone or in combination with other nutrients, on fatigue markers and performance during physical activity.

Glutamine has an array of functions able to potentially reduce fatigue, as shown in the image below.

functions of glutamine

Glutamine has the following functions:

  • Enhances ammonia excretion, metabolism and buffering and reduce ammonia build up

  • Reduces muscle damage

  • Improves fluid and electrolyte absorption

  • Increases glycogen and glutathione synthesis

  • Functions as an energy substrate

In this review, 55 research papers satisfied the inclusion criteria and were analysed.

Although glutamine supplementation improved several fatigue indicators, such as enhanced glycogen synthesis and decreased ammonia buildup, it did not improve physical performance in the majority of the trials reviewed.


Despite the fact glutamine has various functions and ways it could reduce fatigue, glutamine supplementation seems to have little benefits on performance, although it can reduce several fatigue measures.

Do you use glutamine?

  • Yes

  • No

  • I will now

  • I did, but won't anymore



This section contains links to research, studies, and sources of information for this article, as well as authors, contributors, etc. All sources, along with the article and facts, are subjected to a series of quality, reliability, and relevance checks.

Real Muscle primarily uses high-quality sources, such as peer-reviewed publications, to back up the information in our articles. To understand more about how we fact-check and keep our information accurate, dependable, and trustworthy, read more about us.

This evidence based analysis of the anti-fatigue effect of glutamine features 1 reference, listed below.

1. Coqueiro AY, Rogero MM, Tirapegui J. Glutamine as an Anti-Fatigue Amino Acid in Sports Nutrition. Nutrients. (2019, Apr 17) (Review) ✔

Citations with a tick indicate the information is from a trusted source.


The information provided in this article is not intended to replace professional medical advice, diagnosis, or treatment. Always seek the guidance of a physician or other competent professional before following advice or taking any supplement. See our terms and conditions.

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