Written by: ASN



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What is L-Glutamine?

L-glutamine might be one of the best ‘hidden gems’ on the market and plays a massive role in immune health, muscle growth, digestive function and even weight management. So, what is L-glutamine? 

What is L-Glutamine?

Glutamine is an amino acid made in your muscles and transmitted through your body into different organ systems. It’s not just any old amino acid, though. In fact, glutamine is the most abundant amino acid in your body (WebMD).

Glutamine is a building block of protein and plays a critical role in the immune system. While it is produced naturally within your body, you can also find glutamine in many foods or supplements.

Glutamine itself exists in two forms, L-glutamine and D-glutamine, with the form found in foods and supplements being L-glutamine. Playing a crucial role in protein creation and other functions, glutamine is considered a conditionally essential amino acid, meaning that it should be obtained primarily through your diet (Tinsley, G. 2018).

What does L-Glutamine do?

Glutamine is responsible for a vast amount of functions within your body. You’d probably be surprised by just how much L-glutamine contributes to your health.

As the most abundant amino acid in your body, glutamine is a building block of protein. Your body will generally produce enough glutamine to support your needs, but during stressful situations following strenuous exercise or injury, your body may need more glutamine than it can produce.

Glutamine plays an essential role in removing excess ammonia, which is a common waste product in the body, and can help your immune system continue to function at an optimal level. It also supports brain function, digestion, recovery and performance (Mount Sinai).

the benefits of l-glutamine

L-glutamine is a dynamic amino acid that provides a vast range of performance and health benefits, from recovery to digestive health. Let’s take a look at the best ones!

muscle recovery

L-glutamine is a building block of proteins that make up all the tissues in your body and are essential to muscle growth and repair. After a heavy session at the gym, L-glutamine can help you recover and grow muscle by improving the protein synthesis rate within the cells (H&B. 2023).

L-glutamine plays a role in the transportation of nitrogen around the blood, delivering it to muscles, where it can promote muscle growth and support recovery. When you’re pushing yourself beyond your limits during training (which we know you are), the glutamine levels in your blood become depleted. Replenishing your glutamine stocks after exercise is pivotal in ensuring you can get back to training the next day without any soreness, damage or injury (H&B. 2023).

Immune system support

Your immune system plays a pivotal role in protecting your body from harmful substances, germs and diseases that can cause damage to you. Naturally, you’re going to want to take care of your immune system. This is where L-glutamine can once again assist in supporting your health.

Clinical studies have suggested that glutamine supplements can strengthen the immune system and reduce infections and may even play a role in wound healing, burn recovery and response to illness (Mount Sinai).

In addition to its benefits in infection and inflammation, glutamine is essential for cell proliferation and can act as respiratory fuel that can improve the function of stimulated immune cells. Glutamine can be utilised by isolated immune cells like lymphocytes, macrophages and neutrophils, where it is metabolised (Newsholme, P. 2001).

Supports gut health

Don’t ignore your gut. Maintaining a healthy gut is important for your overall well-being as it plays a vital role in digestion, nutrient absorption, immune function, and even mental health.

L-glutamine helps to support and maintain the gut barrier and is a source of fuel for cells in the small intestine and large bowel. This amino acid supports the maintenance of the gut villi and is essential in preventing bacteria from entering the small intestine or bowel wall. It has also been used to treat conditions like Crohn’s disease, celiac disease, short bowel disease, and gastritis (Flesher, M. 2004).

Supports brain health

One of the best benefits of glutamine is the benefits that it offers to your brain health. The brain uses L-glutamine to build and balance GABA, which is the primary inhibitory neurotransmitter in the brain. Evidence suggests that L-glutamine and GABA both play a major role in mood and anxiety disorders and can play a role in reducing symptoms of stress (Roan, M. 2021).

L-glutamine has been referred to as the ‘calming amino acid’ and can be effective in reducing stress-related symptoms of anxiety. Increasing your L-glutamine levels can also help to reduce symptoms of stress-related IBS (Roan, M. 2021).

When should you take L-Glutamine?

The best times to take this supplement are morning, after a workout and before bed. L-glutamine comes unflavoured, which means you can add it to your protein shake or pre-workout with no clash of flavours!

The Best L-Glutamine Supplements

If you’re looking for the best L-glutamine supplements to support your goals, we’ll keep things simple. 

Evolve L-Glutamine delivers a natural dose of rice-fermented L-glutamine, which is the purest and most organic form on the market available. This formula supports gut health, muscle recovery and immune system function and is free of synthetic chemicals or compounds.


ATP Science’s L-Glutamine is HPLC-Tested and supports gut health, immunity, and muscle building, while EHP Labs Glutamine is a pure, micronised form that is 100% bio-available and pharmaceutical-grade to support your performance and recovery.


the run down

L-glutamine is a versatile, convenient and underrated supplement that can take your immune health, performance and recovery to the next level.

Need more help understanding how L-glutamine can support your immunity, gut health, recovery and performance? Visit us in-store or reach out online, and our friendly team can provide guidance and help you choose the best L-glutamine products to support your goals.


WebMD. ‘Glutamine - Uses, Side Effects, and More’, WebMD, accessed 22 May 2023, https://www.webmd.com/vitamins/ai/ingredientmono-878/glutamine

Tinsley, G. 2018, ‘Glutamine: Benefits, Uses and Side Effects’, Healthline, accessed 22 May 2023, https://www.healthline.com/nutrition/glutamine

Holland & Barrett. 2023, ‘L-glutamine and recovery’, H&B, accessed 22 May 2023, https://www.hollandandbarrett.com/the-health-hub/sports-nutrition/l-glutamine-and-recovery/#:~:text=L%2Dglutamine%20is%20often%20used,as%20muscle%20tissues%20and%20skin.

Flesher, M. 2004, ‘What is Glutamine?’ GI Society, accessed 22 May 2023, https://badgut.org/information-centre/health-nutrition/glutamine/

Newsholme, P. 2001, ‘Why Is L-Glutamine Metabolism Important to Cells of the Immune System in Health, Postinjury, Surgery or Infection?’ The Journal of Nutrition, accessed 23 May 2023, https://academic.oup.com/jn/article/131/9/2515S/4687557

Roan, M. 2021, ‘5 L-Glutamine Benefits For Your Gut, Brain, Muscles And More’, Human Performance Hub, accessed 23 May 2023, https://humanperformancehub.co.uk/resources/l-glutamine-benefits-for-your-gut-brain-muscles-and-more/#:~:text=L%2Dglutamine%20Helps%20Reduce%20Symptoms,can%20cause%20serious%20health%20problems.