L-Glutamine: Unlocking Cognitive Potential as a Nootropic Supplement"

What Is L Glutamine?


L Glutamine is a naturally occurring amino acid that plays a crucial role in various physiological processes within the human body. It is considered a non-essential amino acid, which means that it can be synthesized by the body itself. L Glutamine is found abundantly in the muscles and bloodstream, and it serves as a vital source of energy for cells.

L Glutamine has several essential functions in the body. It plays a key role in protein synthesis, aiding in the repair and growth of muscle tissues. Additionally, it supports immune system function by providing energy to immune cells, such as lymphocytes and macrophages. It is naturally found in cabbage, raw parsley, milk, cheese, yogurt, pork and  beef.

Recently, L glutamine has gained attention as a nootropic, as it has been shown effective in tackling numerous neurological disorders.


The Potential Impact of L-Glutamine on the Brain

Memory And Learning

There is conflicting clinical evidence regarding the potential benefits of glutamine on memory and learning.

One trial conducted on rats explored the effects of glutamine, aspartic acid, and arginine supplementation, revealing improved memory and learning abilities. Additionally, there was an increase in brain nitric oxide synthase (NOS) activity, and the modulation of N-methyl-D-aspartate (NMDA) receptors, which play a significant role in memory formation[1].

Another study suggested that glutamine, in combination with insulin, enhanced the expression of PI3K in cells exposed to high glucose levels. This increase in PI3K-Akt signaling within the central nervous system has been associated with improved memory in both mouse and human trials[2].

While these studies provide a theoretical foundation for the potential cognitive benefits of glutamine, further research is required to solidify these claims.

Improves Symptoms Of Depression

Research suggests that lower levels of glutamine are associated with cases of major depressive disorder. In a preliminary trial involving 43 adults with various forms of depressive, neurasthenic, and dissociative illnesses, glutamine demonstrated clear antidepressant properties[3].

The researchers speculated that glutamine's role as a precursor of GABA, a neurotransmitter known for its calming effects, may explain its anti-depressive properties.

Additionally, studies conducted on mice have shown that glutamine can alleviate symptoms of depression. One such study found that depressive behaviors induced by chronic stress were linked to decreased activity in glutamatergic neurons in the medial prefrontal cortex, resulting from low levels of glutamate and glutamine[4].

 The researchers concluded that supplementing with glutamine could serve as an alternative antidepressant by enhancing glutamatergic neurotransmission [5]. However, further research is needed to establish glutamine's effectiveness in treating depression, and it is important to consult with a healthcare professional before considering any dietary supplements for depressive symptoms.


L-Glutamine's Potential Role in ADHD

Studies have found lower levels of glutamine in adults with ADHD compared to those without the condition, suggesting a potential link between glutamine and ADHD[6,7]. While there is a possibility that supplementation may help treat ADHD, it is important to note that there have been no clinical trials directly indicating glutamine's effectiveness in improving ADHD symptoms

Some anecdotal evidence exists, but further research is necessary to establish its efficacy. If considering glutamine supplementation for ADHD, it is advisable to consult with a healthcare professional for guidance and to explore comprehensive treatment options.

Other Potential Benefits of L-Glutamine

Boosts Physical Performance

L-Glutamine has gained popularity as a supplement for exercise and physical performance. Clinical trials have shown that it can enhance Human Growth Hormone (HGH) and growth factor-I levels, potentially improving athletic ability, muscle growth, and recovery[8]. Weightlifters and bodybuilders often use L-glutamine to replenish depleted stores caused by intense exercise.

Promotes Gut And Immune Health

Additionally, L-glutamine offers benefits for gut health and the immune system. It reduces the production of pro-inflammatory cytokines in the intestines, which is beneficial for inflammatory bowel disease (IBD)[9].

 It also promotes the production of zonulin, regulating gut permeability and preventing leaky gut, which can contribute to immune dysfunction and autoimmunity. Furthermore, L-glutamine serves as fuel for the immune system, and maintaining adequate levels is crucial for optimal immune cell function and overall health.

How to Take L-Glutamine

To maximize the benefits of L-Glutamine supplementation, it is recommended to follow these guidelines:

  • Choose high-quality supplements from reputable brands.
  • Follow the recommended dosage instructions.
  • Take L-Glutamine with meals to enhance absorption.
  • Consider combining L-Glutamine with other nutrients or supplements for synergistic effects.
  • Timing and Frequency of Supplementation

L-Glutamine can be taken once daily or divided into multiple doses throughout the day. The timing of supplementation may vary based on individual preferences and health goals. It is advisable to maintain consistency in dosage and timing for optimal results.


Personal Experiences

Many individuals have reported positive experiences with L-Glutamine supplementation. Some have found relief from anxiety symptoms, improved mood stability, enhanced cognitive function, and better metabolic health.

One user shared, “L-glutamine has been a life changer for me, no more urgency and stress around finding a bathroom constantly. I can enjoy all sorts of foods that used to irritate my gut. I take this in conjunction with a few other products which I will list here for those who are on their leaky gut IBS journey.

I take - super enzymes by Now - with every meal(will dial this back eventually once my gut is more healed) - PRO-15 probiotic by hyper biotics (almost instant results. produced first firm stool in years, 1 day after use) - a good multi-vitamin at a low dose as to not cause any irritation(using opti-men multi with great results).

I feel much better with stress tolerance and no urgent movements. no loose movements. no mucus in stool. I have been trying to find solutions for a long time. I hope this helps some people suffering”.

Comparisons with Other Supplements

L-Glutamine differs from certain other supplements in terms of its specific health benefits and mechanisms of action. For instance, compared to omega-3 fatty acids, L-Glutamine focuses more on mental health and metabolic support rather than cardiovascular health. Understanding these distinctions can help in selecting the appropriate supplement based on individual health goals.



There are currently no established dosage recommendations for l-glutamine as a nootropic. However, when used as a sports nutrition supplement, L-Glutamine is commonly taken in daily doses ranging from 1 g to 5 g.

Potential Side Effects

When it comes to side effects, l-glutamine is generally considered safe and well-tolerated, given its presence in various foods and the human body. Nevertheless, it is important to exercise caution in dosing, as excessive levels of l-glutamine have been associated with an increase in the neurotoxin ammonia in the body.

Future Research

While there is already a significant body of research supporting the cognitive-enhancing benefits of, l-glutamine, there is still much to be learned about this plant and its potential uses. Future research may explore the effects of, l-glutamine on other aspects of health and wellness, as well as potential long-term effects and optimal dosages.



Overall glutamine is a promising nootropic supplement with a range of cognitive-enhancing benefits, as well as potential applications in other areas of health and wellness.

 While it is generally considered safe, it is important to consult with a healthcare provider before taking, l-glutamine, especially if you have any medical conditions or are taking any medications. With proper use and supervision, L-glutamine may be a valuable tool for improving cognitive function and overall well-being.


  1. Jing H, Cheng Y, Li S, Zhang G.. Effects of glutamate and glutamine on learning and memory of rats Wei Sheng Yan Jiu. 2000.
  2. Caijuan Wang, et al. Glutamine Enhances the Hypoglycemic Effect of Insulin in L6 Cells via Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (AKT)/Glucose Transporter 4 (GLUT4) Signaling Pathway Med Sci Monit. 2018.
  3. Gabbouj S, et al. Altered Insulin Signaling in Alzheimer’s Disease Brain – Special Emphasis on PI3K-Akt Pathway Journal or Front Neurosci. 2019
  4. Choudary PV, et al. Altered cortical glutamatergic and GABAergic signal transmission with glial involvement in depression Proc Natl Acad Sci U S A. 2005
  5. Cocchi R. Antidepressive properties of I-glutamine. Preliminary report Acta Psychiatr Belg. 1976
  6. AYounghyurk Lee, et al. Glutamine deficiency in the prefrontal cortex increases depressive-like behaviors in male mice J Psychiatry Neurosci. 2013
  7. S Maltezos, et al. Glutamate/glutamine and neuronal integrity in adults with ADHD: a proton MRS study Transl Psychiatry. 2014
  8. Arwert LI, Deijen JB, Drent ML. Effects of an oral mixture containing glycine, glutamine, and niacin on memory, GH, and IGF-I secretion in middle-aged and elderly subjects Nutr Neurosci. 2003
  9. Clément L’Huillier, et al. Glutamine, but not Branched-Chain Amino Acids, Restores Intestinal Barrier Function during Activity-Based Anorexia Nutrients. 2019

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