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Home / Nootropics List / L-Glutamine
Avatar for David Tomen
Author: David Tomen | Nootropics Expert Founder Modified: September 02, 2023

David Tomen is a nootropics expert and author of the influential "Head First – The Complete Guide to Healing & Optimizing Your Brain with Nootropic Supplements" and ‘Secrets of the Optimized Brain’.  David also runs the popular Nootropics Expert YouTube channel.

July 5, 2023 By David Tomen 126 Comments

L-Glutamine

L-Glutamine
L-glutamine can help improve alertness, concentration, focus, memory and mood, boost Human Growth Hormone and reduce anxiety
Key Takeaways
  1. L-glutamine is a conditionally essential amino acid, vital for brain function, as it serves as a precursor to neurotransmitters glutamate and GABA.

  2. Glutamine plays multiple essential roles in the body, including protein synthesis, muscle growth, immune system function, neurotransmitter synthesis, and glucose metabolism.

  3. L-glutamine supplementation can positively impact human growth hormone levels, muscle recovery, and intestinal permeability in inflammatory bowel disease.

  4. Maintaining a balance between glutamine and glutamate/GABA is crucial for optimal brain health, as disruptions can lead to various brain conditions and neurodegenerative diseases.

  5. L-glutamine supplementation can improve concentration, focus, memory, mood, and overall brain performance.

L-glutamine is a conditionally essential amino acid and main precursor for the production of the neurotransmitters glutamate and GABA (γ-aminobutyric acid) in your brain.

Glutamine is the most abundant amino acid in your body. And is involved in many of your bodily functions. Including much of the activity in your brain.[i] But L-glutamate is the most abundant amino acid in your brain. And the balance of these two is critical for optimal brain function.

The function of the glutamine/glutamate cycle is involved in protein synthesis, precursors for muscle growth, regulation of the acid-base balance in your kidneys, provides oxidative fuel for your intestine and immune system cells, provides nitrogen transport between organs, acts as precursors to neurotransmitter synthesis, nucleotide and nucleic acid synthesis for glutathione production, and glucose metabolism.[ii]

L-glutamine supplementation is mostly talked about in athletic and body building circles for its effect on human growth hormone and muscle recovery after a workout, or for its effects on inflammatory bowel disease (IBD) for its reduction in intestinal permeability. But L-glutamine is largely ignored by the nootropics community.

L-glutamine is so critically important to the optimized brain that by reading this post, you’ll understand why it may be an important addition to your nootropic stack.

L-glutamine helps:

  • Neurotransmitters. L-glutamine is a precursor to the excitatory amino acid and neurotransmitter glutamate and aspartate. And the inhibitory amino acid and neurotransmitter GABA.  Affecting alertness, concentration, focus, memory and mood.
  • Brain Inflammation. L-glutamine helps boost your body’s immune response. Increasing antibodies to fight against viruses and bad bacteria. L-glutamine helps tame inflammatory cytokines. And L-glutamine detoxes the brain from excess ammonia and converts it into other amino acids, sugars and urea.
  • Stress. L-glutamine supplies energy to immune and intestinal cells. Not enough glutamine and these cells become sluggish and can’t function properly. Supplementary L-glutamine is especially important during times of stress, tension and physical strain.

Table of Contents

  • Overview
  • How does L-Glutamine work in the Brain?
  • How things go bad
  • L-Glutamine benefits
  • How does L-Glutamine feel?
  • L-Glutamine Clinical Research
    • L-glutamine Increases Human Growth Hormone
    • L-glutamine Improves Cerebral Performance
  • L-Glutamine Nootropic Recommended Dosage
  • L-Glutamine Side Effects
  • Types of L-Glutamine to Buy
  • Nootropics Expert Recommendation

Overview

L-glutamine is an essential amino acid and precursor for the production of glutamate. Glutamate is the most abundant neurotransmitter in your brain.

l-glutamine chemical structure
L-glutamine

As an ‘excitatory’ neurotransmitter, glutamate is released from pre-synaptic cells and then binds to post-synaptic cells inducing activation. Too much glutamate and neurons become overactive causing a toxic environment that is harmful to neurons. And to cognition.

To keep this process in check, glutamate is also a precursor to the ‘inhibitory’ neurotransmitter GABA. GABA works by preventing neural signaling in over-excited neurons caused by glutamate that could result in anxiety and depression.[iii]

The balance of glutamine and glutamate has been identified in an array of brain conditions (i.e. mental illness, tumor, neurodegeneration) as well as in normal brain function.[iv]

The precursor relationship between glutamine and glutamate/GABA is often referred to in scientific and research circles as the Gln/Gly(GABA) cycle.[v] Glutamine is naturally synthesized from glutamate and ammonia in brain cells called astrocytes in a reaction catalyzed by glutamine synthetase (GS).

Newly synthesized glutamine is transferred to neurons and hydrolyzed by phosphate-activated glutaminase (PAG) to then produce glutamate. A portion of which may be decarboxylated to GABA or transaminated to Aspartate.

Glutamate, the excitatory neurotransmitter and GABA, the calming neurotransmitter rely on this cycle to maintain homeostasis within your brain. Glutamine also modulates the synthesis of Nitric Oxide by controlling the supply of its precursor arginine.

When this cycle gets out of whack, things start to break down. The results can be particularly nasty. And result in conditions like epilepsy, or hepatic encephalopathy which effects behavior, mood, speech, sleep and the way you move.

L-glutamine becomes a “conditionally” essential amino acid when your body can’t produce enough on its own. And you need to replenish L-glutamine levels either through supplementation or food.[vi]

L-glutamine can be found in foods such as beef, pork, fish, eggs, milk and dairy products, wheat, cabbage, beets, beans, spinach and parsley.

l-glutamine supplementation can help improve mood

How does L-Glutamine work in the Brain?

L-glutamine helps brain health and function in several ways. But two in particular stand out.

  1. L-glutamine is critical for an optimized brain. L-glutamine is a precursor to the neurotransmitter glutamate in your brain. The balance of glutamine and glutamate is crucial to an optimized and healthy brain.

    The normal cycling of glutamine and glutamate takes a huge amount of energy in the brain. Research has estimated that the Gln/Gly(GABA) cycle accounts for more than 80% of cerebral glucose consumption.[vii] So when you’re using nootropics like Resveratrol or PQQ to boost mental energy, much of that energy is going towards maintaining this Gln/Gly(GABA) cycle.

    A disruption of this cycle results in all kinds of problems including Reye’s Syndrome, epilepsy, bipolar disorder, schizophrenia, anxiety, depression, and alcohol addiction.[viii]

    One Korean study measured Glutamate and Glutamine concentrations in the prefrontal cortex of mice infused with an astrocyte toxin. And they used other inhibitors to disrupt the Glu/Gln cycle.

    Glutamate and glutamine levels decreased on the 5th day in the mice. The animals experienced immobility and a decreased preference for sucrose (sugar). A sure indication in mice of depression.

    Direct infusion of L-glutamine completely reversed all the impairments that were originally induced in the animals. And the researchers concluded that neuronal deficiency of L-glutamine causes depression.[ix]

  2. L-glutamine also helps prevent brain aging. Researchers have long been on the hunt to determine what causes the human brain to age. Recently, mitochondrial dysfunction has been implicated in the loss of brain function in neurodegenerative diseases and aging.[x] Leading to an abnormal increase in the excitatory neurotransmitter glutamate.

    A study at the New York University School of Medicine used 28 patients with mild traumatic brain injury and 22 matched controls. Gray and white matter in their brains was measured using MRI’s.

    The study found that one year after traumatic brain injury there was significant global brain atrophy. Much larger than in the control subjects.

    The team noted the amount of brain damage from just one concussion. And that this type of injury was not exclusive to a severe blow to the head. Even mild injury could cause brain damage.[xi] Most of the damage was associated with a disrupted Glu/Gln cycle and an abnormal increase in glutamate levels.[xii]

    How things go bad

    Low levels of L-glutamine are associated with a variety of health problems.L-glutamine relieves anxiety

    ↓ Cellular energy drops and immune system weakens

    ↓ Short- and long-term memory declines

    ↓ Mood and anxiety disorders, insomnia, and lack of concentration

    ↑ Muscle spasms, hypertension, convulsion, Tourette’s Syndrome and epilepsy

    ↑ Ammonia levels rise in brain cells[xiii]

    ↓ Poor digestion, bloating, flatulence, and constipation

    When your neurotransmitters, including L-glutamine and glutamate are in balance, you feel motivated, productive and energetic. And you feel calm and relaxed during downtime.

    When L-glutamine levels are low you feel filled with dread, you’re constantly worried, you have racing thoughts, and you’re frequently late and disorganized.

    Many people in this L-glutamine -slump resort to high carbohydrate foods, and drugs or alcohol to relax.

    L-Glutamine benefits

    The amino acid L-glutamine is the precursor to L-glutamate production in your body. L-glutamate gets converted to GABA.

    L-Glutamine improves concentration and focusGlutamate is your body’s most abundant excitatory neurotransmitter. Which is responsible for attention span, brain energy, learning ability, memory, and staying awake.

    An enzyme called glutamate decarboxylase converts glutamate to GABA. It does it with the help of the active form of Vitamin B6 (Pyridoxal-5-Phosphate (P5P)).

    The amino acid taurine helps increase the communication and productivity of this enzyme. And zinc helps the release of GABA from its receptors.

    When this Gln/Gly(GABA) cycle works efficiently, you feel relaxed with no stress or feelings of anxiety. Detoxification of your liver results in a more restful night’s sleep. Focus, concentration, memory and mood all improve.

    How does L-Glutamine feel?

    During times of chronic, long-term stress caused by physical exertion or illness, glutamine levels in your body can drop by 50% or more.[xiv]

    Supplementing with L-glutamine can improve your quality of life, increase energy levels, reduce muscle aches, improve digestion and gut health, improve quality of sleep, and reduce pain and fatigue.

    When you balance L-glutamine levels in your brain, you feel relaxed and calm. Cravings for sugar and alcohol will decline.

    L-glutamine will help in recovery from workouts and improve performance. You may find it easier to lose weight.

    Many neurohackers use L-glutamine to help heal Leaky Gut Syndrome and reduce the symptoms of Crohn’s and Celiac Disease.

    As a nootropic, L-glutamine can help improve alertness, concentration, focus, memory and mood.

    l-glutamine can help increase Human Growth Hormone

    L-Glutamine Clinical Research

    L-glutamine was identified as a neurotransmitter several decades ago. And there has been a lot of research on L-glutamine published since. But most of it is focused on strength training and maintaining muscle mass in athletes. And for people healing from surgery or recovering from illness.

    But L-glutamine can be a powerful nootropic as well. Here are a couple of studies looking at L-glutamine for brain health.

    L-glutamine Increases Human Growth Hormone

    Bodybuilders and athletes use supplementary L-glutamine to help repair and build muscle. And there are several studies supporting the notion that L-glutamine increases Human Growth Hormone.

    In one study, researchers worked with 9 healthy subjects and gave them 2 grams of L-glutamine in a cola drink. Blood samples were taken before drinking the cola-spiked drink, then again at 30 mins., 60 and 90 mins.

    The researchers found that both blood L-glutamine and human growth hormone levels were significantly higher than before taking L-glutamine. The team concluded that “a surprisingly small oral L-glutamine load was capable of elevating growth hormone”.[xv]

    Human growth hormone and Brain-Derived Neurotrophic Factor (BDNF) are intricately linked. BDNF is involved in Long-Term Potentiation and the encoding of long-term memories.

    L-glutamine Improves Cerebral Performance

    Lack of concentration and poor memory can be improved by supplementing with L-glutamine with Vitamin B3 (niacin). Some of the glutamine in your blood is transformed into glutamic acid in your brain.

    Glutamic acid functions first as fuel, but it also gets rid of excess ammonia by binding to this cellular toxin and converting it into glutamine.

    A study in the Netherlands conducted a randomized, double-blind, placebo controlled trial with 42 healthy men and woman aged 40 – 76 years. Subjects received a 5-gram stack containing glycine, L-glutamine and niacin twice daily for 3 weeks.

    The L-glutamine stack increased Human Growth Hormone a whopping 70% compared to placebo. But surprisingly it wasn’t the growth hormone that improved memory and vigor. It was insulin-like growth factor-I that improved memory and vigor. Attributed to the L-Glutamine stack the subjects took for 3 weeks.[xvi]

    L-Glutamine Nootropic Recommended Dosage L-glutamine nootropic dosage

    Most people don’t get enough L-glutamine from food alone. And why adding L-glutamine to your nootropic stack can boost your immune system, improve your ability to fight infection and diseases, and boost cognition.

    The recommended daily dosage of L-glutamine is 2 to 5 grams per day.

    Serious power athletes often dose up to 10 grams of L-glutamine per day.

    L-Glutamine Side Effects

    L-glutamine is considered very safe when taken in normal recommended doses.

    Rarely do people report side effects like nausea, vomiting, flatulence, abdominal pain, constipation, dry mouth, hemorrhoids, dizziness, depression, skin rashes, insomnia and increased sweating. Remember, the balance between L-glutamine and glutamate (Gln/Gly(GABA) cycle) is critical for optimal health.

    Some recent research has shown that L-glutamine can stimulate tumor growth. So if you are dealing with any form of cancer you should not use L-glutamine.

    If you are dealing with cirrhosis of the liver, you should avoid L-glutamine. If you have severe liver disease that includes difficulty thinking or confusion (hepatic encephalopathy), don’t use L-glutamine.

    If you are allergic or sensitive to Monosodium Glutamate (MSG), you may be sensitive to L-glutamine because your body converts it to glutamate.

    And if you have a severe mental disorder including mania or frequently have seizures you may want to avoid L-glutamine.

    Types of L-Glutamine to Buy

    L-glutamine as a supplement is available in tablet, capsule and powder.

    The most commonly available form of L-glutamine as a nootropic supplement is called “free form” glutamine.

    Trans-Alanyl or Alanyl-L-glutamine is an amino acid attached to another amino acid which aids in digestion of this supplement.

    If you are using it to boost athletic performance and speed recovery, both forms of L-glutamine are best taken right before or after a workout. Using it with small meals before or after your workout session can help support your metabolism and weight loss goals. And will assist in muscle building, recovery and maintenance.

    As a nootropic I recommend: Life Extension – L-Glutamine

    Nootropics Expert Recommendation

    L-Glutamine 2 – 5 grams per day.

    Nootropics Expert Tested and ApprovedI recommend using L-glutamine as a nootropic supplement if you’re dealing with anxiety or stress. And to calm or keep in check some of the stimulatory effects of some nootropics.

    Your body does make L-glutamine on its own from glutamate in your brain. But most people do not maintain an adequate supply of L-glutamine in their system.

    And if you’re dealing with illness, recovery from surgery, strenuous physical activity like working out, Leaky Gut Syndrome, Crohn’s or Celiac Disease, and need some help in recovery, L-glutamine can help.

    L-glutamine also helps to curb the desire for sugar, carbs and alcohol.

    We suggest trying a L-glutamine supplement first at a dose of 500 mg. And see how you react. You can safely dose up to 20 grams of L-glutamine per day. But most neurohackers find much lower doses effective for boosting cognition, mood and memory.

    As a nootropic I recommend: Life Extension – L-Glutamine

    REFERENCES

    [i] Chwals W.J. “Regulation of the cellular and physiological effects of glutamine.” Mini Revues in Medicinal Chemistry. 2004 Oct;4(8):833-8. (source)

    [ii] Newsholme P., Lima M.M., Procopio J., Pithon-Curi T.C., Doi S.Q., Bazotte R.B., Curi R. “Glutamine and glutamate as vital metabolites.”Brazilian Journal of Medical and Biological Research. 2003 Feb;36(2):153-63. (source)

    [iii] Petroff O.A. “GABA and glutamate in the human brain.”Neuroscientist. 2002 Dec;8(6):562-73. (source)

    [iv] Ramadan S., Lin A., Stanwell P. “Glutamate and Glutamine: A Review of In Vivo MRS in the Human Brain” NMR Biomed. 2013 Dec; 26(12): 10.1002/nbm.3045. (source)

    [v] Albrecht J., Sidoryk-Węgrzynowicz M., Zielińska M., Aschner M. “Roles of glutamine in neurotransmission.” Neuron Glia Biology. 2010 Nov;6(4):263-76 (source)

    [vi] Tapiero H., Mathé G., Couvreur P., Tew K.D. “Glutamine and glutamate.” Biomédecine and Pharmacotherapy. 2002 Nov;56(9):446-57. (source)

    [vii] Sibson N.R., Dhankhar A., Mason G.F., Rothman D.L., Behar K.L., Shulman R.G. “Stoichiometric coupling of brain glucose metabolism and glutamatergic neuronal activity.” Proceedings of the National Academy of Sciences U S A. 1998 Jan 6;95(1):316-21. (source)

    [viii] De Witte P. “Imbalance between neuroexcitatory and neuroinhibitory amino acids causes craving for ethanol.” Addiction and Behavior. 2004 Sep;29(7):1325-39. (source)

    [ix] Lee Y., Son H., Kim G., Kim S., Lee D.H., Roh G.S., Kang S.S., Cho G.J., Choi W.S., Kim H.J. “Glutamine deficiency in the prefrontal cortex increases depressive-like behaviours in male mice.” Journal of Psychiatry and Neuroscience. 2013 May;38(3):183-91. (source)

    [x] Lin M.T., Beal M.F. “Mitochondrial dysfunction and oxidative stress in neurodegenerative diseases.” Nature. 2006 Oct 19;443(7113):787-95. (source)

    [xi] Zhou Y., Kierans A., Kenul D., Ge Y., Rath J., Reaume J., Grossman R.I., Lui Y.W. “Mild traumatic brain injury: longitudinal regional brain volume changes.” Radiology. 2013 Jun;267(3):880-90. (source)

    [xii] Boumezbeur F., Mason G.F., de Graaf R.A., Behar K.L., Cline G.W., Shulman G.I., Rothman D.L., Petersen K.F. “Altered brain mitochondrial metabolism in healthy aging as assessed by in vivo magnetic resonance spectroscopy.” Journal of Cerebral Blood Flow and Metabolism. 2010 Jan;30(1):211-21 (source)

    [xiii] Suárez I., Bodega G., Fernández B. “Glutamine synthetase in brain: effect of ammonia.” Neurochemistry International. 2002 Aug-Sep;41(2-3):123-42. (source)

    [xiv] Mittendorfer B., Volpi E., Wolfe R.R. “Whole body and skeletal muscle glutamine metabolism in healthy subjects” American Journal of Physiology, Endocrinology and Metabolism. 2001 Feb; 280(2): E323–E333. (source)

    [xv] Welbourne T.C. “Increased plasma bicarbonate and growth hormone after an oral glutamine load.” American Journal of Clinical Nutrition. 1995 May;61(5):1058-61. (source)

    [xvi] Arwert L.I., Deijen J.B., Drent M.L. “Effects of an oral mixture containing glycine, glutamine and niacin on memory, GH and IGF-I secretion in middle-aged and elderly subjects.” Nutritional Neuroscience. 2003 Oct;6(5):269-75. (source)

     

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    Filed Under: Nootropics List

    Avatar for David Tomen

    About David Tomen

    David Tomen is a nootropics expert and author of the influential "Head First – The Complete Guide to Healing & Optimizing Your Brain with Nootropic Supplements" and ‘Secrets of the Optimized Brain’.  David also runs the popular Nootropics Expert YouTube channel.

    Comments

    1. Avatar for ClaudiaClaudia says

      December 21, 2022 at 1:24 pm

      Hi David,

      I seem to get headaches from L-Glutamine, probably because I’m sensitive to MSG which also seems to give me headaches
      Is there something I can take to combat this?
      I’ve tried to just deal with it since I’ve noticed a significant change in gut health when I take L-Glutamine, but the daily headaches are a real pain

      Reply
      • Avatar for David TomenDavid Tomen says

        December 21, 2022 at 1:55 pm

        Claudia, if you are allergic or sensitive to Monosodium Glutamate (MSG), you may be sensitive to L-glutamine because your body converts it to glutamate. And there is nothing you can do other than stop using L-Glutamine.

        See my article on how to heal a leaky blood-brain barrier here: https://nootropicsexpert.com/how-to-heal-a-leaky-blood-brain-barrier/. Because it is the very same type of barrier protecting your gut. There could be something in that article that can help you.

        Reply
        • Avatar for ClaudiaClaudia says

          December 22, 2022 at 5:22 am

          Thank you for your quick reply!

          Reply
    2. Avatar for Marcie WebberMarcie Webber says

      December 4, 2022 at 2:00 pm

      Which L glutamine is better choice, Life Extension or Pure Encapsulation free form? Is there any difference in formulation?
      Is one better for brain support and the other for gut health?

      Reply
      • Avatar for David TomenDavid Tomen says

        December 4, 2022 at 2:23 pm

        Marcie, I prefer Pure Encapsulations Glutamine (https://geni.us/wFGS83) because it does not contain magnesium stearate.

        Reply
    3. Avatar for Marcie WebberMarcie Webber says

      December 3, 2022 at 12:54 pm

      Thanks again David. Thanks for great info. I was recently diagnosed with CT scan of bad inflammation in my large intestines and this supplement helps plus the brain power. Love you.

      Reply
      • Avatar for David TomenDavid Tomen says

        December 4, 2022 at 1:12 pm

        Thanks Marcie.

        Reply
    4. Avatar for Marcie webberMarcie webber says

      November 28, 2022 at 12:57 am

      Hi David!
      Can L glutamate be taken together with Taurine?
      Are they both long term?

      Reply
      • Avatar for David TomenDavid Tomen says

        November 28, 2022 at 1:37 pm

        Marcie, I think you mean L-Glutamine and yes it can be use long-term with Taurine as long as it works for you.

        Reply
    5. Avatar for ClaudiaClaudia says

      November 17, 2022 at 3:06 pm

      Hi David,

      Is it true that we need to take L-Glutamine ahold hour before or two hours after a meal?

      Reply
      • Avatar for David TomenDavid Tomen says

        November 19, 2022 at 2:04 pm

        Claudia, I have not seen any clinical evidence showing you will absorb more L-Glutamine if you take it well before and well after a meal. The dose if high enough when using L-Glutamine that it will over-power any transporter that is potentially being used by amino acids from the food you eat.

        Reply
        • Avatar for ClaudiaClaudia says

          November 20, 2022 at 5:57 am

          Thank you so much!

          Reply
    6. Avatar for RonRon says

      September 9, 2022 at 7:41 pm

      Hello David,

      Do you think L glutamine would be a good adjunct to Quillichew?

      Is there anything that depletes L glutamine?

      Ron

      Reply
      • Avatar for David TomenDavid Tomen says

        September 13, 2022 at 4:49 pm

        Ron, the Gln/Gly(GABA) cycle accounts for more than 80% of cerebral glucose consumption. If that cycle gets messed up it’ll definitely have a negative effect on someone with ADHD. And the way Quillichew (extended release Ritalin) works.

        Excess glutamate will deplete glutamine. The way to counter that is to supplement with L-Glutamine.

        Reply
        • Avatar for RonRon says

          September 22, 2022 at 5:01 pm

          David, thank you very much!

          Reply
        • Avatar for RonRon says

          October 8, 2022 at 5:09 pm

          David,

          Do you know if NAC depletes L-glutamine?

          Reply
          • Avatar for David TomenDavid Tomen says

            October 9, 2022 at 1:23 pm

            Ron, NAC regulates the amount of glutamate in your brain. It doesn’t deplete it. But it does prevent it from causing glutamate toxicity.

            Reply
            • Avatar for RonRon says

              October 15, 2022 at 9:55 pm

              David, glutamate is in the brain and glutamine us in the body. Is that correct? Does NAC regulate glutamine and glutamate?

            • Avatar for David TomenDavid Tomen says

              October 22, 2022 at 3:46 pm

              Ron, the function of the glutamine/glutamate/GABA cycle is involved in protein synthesis, precursors for muscle growth, regulation of the acid-base balance in your kidneys, provides oxidative fuel for your intestine and immune system cells, provides nitrogen transport between organs, acts as precursors to neurotransmitter synthesis, nucleotide and nucleic acid synthesis for glutathione production, and glucose metabolism.

              I suggest you scroll back up and read this entire review to get a clear understanding on how this works in your brain and body. it’s why I wrote the review.

    7. Avatar for Gary SmithGary Smith says

      August 20, 2022 at 2:03 pm

      Hi David, I have tried Jarrows 5 g of l-glutamine in the past and I sort of felt like it made my depression worse. I have IBS and maybe leaky gut and want to try it again. I am going to buy caps in the 500 mg range.

      For a few weeks now, I have been taking l-tryptophan and GABA to work with my almost three years of insomnia. I have upped the tryptophan to 2,000 mgs and the GABA to 1500 mgs. If I don’t fall asleep within an hour I add another 500 mgs of GABA and if I am awake in the 3 am to 4 am period I add 1,000 mgs more of GABA.

      I’m hoping I am not overdoing the doses on both the GABA and trptophan. I think they are helping but I had surgery a couple of weeks ago and sleep has regressed due to pain, etc.

      My question is will the glutamine mess up this equation since it ultimately produces GABA?

      Reply
      • Avatar for David TomenDavid Tomen says

        August 21, 2022 at 10:36 am

        Gary, if you scroll up you will see a description of the glutamine/glutamate/GABA cycle which is critically important. But too high a dose of anything is never a good idea.

        For example, consistent high doses of L-Tryptophan will upset your serotonin/dopamine balance. High serotonin suppresses dopamine. Which will have a negative effect on sleep.

        Try this for sleep: magnesium Bisglycinate 400 mg, L-Tryptophan 500 or 1,000 mg, PharmaGABA 250 – 500 mg, Lemon Balm 400 mg, L-Theanine 300 mg, and CBD Oil “calm” gummies (2 or 4) (https://bit.ly/3dH6Ndx) about 60 minutes before bed. Use L-Glutamine 500 mg twice per day during the day but not before bed.

        Reply
        • Avatar for Gary SmithGary Smith says

          August 21, 2022 at 11:21 am

          Hi David, thank you. You prefer pharmaGABA over GABA? I had used Thorne’s PG 100 and 200 mg and did not find it helpful. I also feel like it made my depression worse. Maybe not? If you think I should switch to PG, which product do you recommend? I am currently using Double Wood’s GABA 500 mg.

          I will cut back on the tryptophan. I honestly feel like the GABA has been more effective for the insomnia than the tryptophan.

          Reply
          • Avatar for David TomenDavid Tomen says

            August 21, 2022 at 2:50 pm

            Gary, you can use much lower doses of PharmaGABA and it is effective. This is the one I use: https://geni.us/KOYKKYL (Amazon)

            Reply
            • Avatar for Gary SmithGary Smith says

              August 21, 2022 at 3:09 pm

              What dose would you take of the pharmaGABA since I am taking around 3000 mg over night?

            • Avatar for David TomenDavid Tomen says

              August 23, 2022 at 4:39 pm

              If you are using GABA 3,000 mg then likely PharmaGABA 600 mg.

    8. Avatar for RagnarRagnar says

      August 20, 2022 at 6:08 am

      Hope You are doing well David!

      May I ask how NAC and Glutamine/glutamate regulation in brain are related?

      Also Is there any way to support glutamate System in brain (for LTP specially) without having 2-5g of glutamine every day? (looking for something that I can fit in a capsule with my other nootropics)
      What do you think on l-pyroglutamic acid?

      Thanks for your help and wish you the best.

      Reply
      • Avatar for David TomenDavid Tomen says

        August 21, 2022 at 10:47 am

        Ragnar, NAC and glutamate: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6182588/

        You do not need a high dose of L-Glutamine to increase glutamate. Your brain will take care of this itself as long as it has enough L-Glutamine. But no higher than 3 grams per day.

        Reply
    9. Avatar for betty Liebbetty Lieb says

      August 14, 2022 at 11:01 pm

      David, I was wondering if you could speak to the impact on blood sugar levels. This supplement makes mine SPIKE!!! I use it for IBS but, not sure if I should continue because of the possible inflammation it will cause to other parts of my body. I have heart disease so I keep close tabs on my blood sugar levels. Thanks so much.

      Reply
      • Avatar for David TomenDavid Tomen says

        August 16, 2022 at 4:34 pm

        Betty, you can try adding GABA (PharmaGABA) which should balance your glutamine/glutamate/GABA cycle. But the best thing I’ve found to control blood sugar by far is Berberine (https://nootropicsexpert.com/berberine/).

        Reply
    10. Avatar for SandraSandra says

      July 24, 2022 at 4:43 am

      Hi Davdi!

      Are symptoms of low GABA and Glutamine the same?

      Reply
      • Avatar for David TomenDavid Tomen says

        July 24, 2022 at 5:38 pm

        In general they are similar because both are part of the glutamine/glutamate/GABA cycle.

        Reply
    11. Avatar for AlexaAlexa says

      April 18, 2022 at 8:53 pm

      Hi David! So Glutamine is best to be taken during the day for a mild cognitive boost? Gaba makes me very drowsy.

      Reply
      • Avatar for David TomenDavid Tomen says

        April 19, 2022 at 3:32 pm

        Alexa, correct because it does not directly increase GABA. GABA on the other hand directly increases physical levels of GABA in your system.

        Reply
        • Avatar for SaraSara says

          October 2, 2022 at 7:41 pm

          Hi David, I started taking 1000mg of L-glutamine bc I read it helps with sugar cravings. I take it in the morning and I haven’t noticed a difference in cravings but have noticed I’m more tired. In researching if I can take more later in the day bc at night is when I want to eat more, I’ve read conflicting articles that it gives you energy and it helps you sleep. Could you help me understand this better? Thank you

          Reply
          • Avatar for David TomenDavid Tomen says

            October 4, 2022 at 3:28 pm

            Sara, using L-Glutamine as a supplement goes on to produce glutamate which then produces GABA and then Human Growth Hormone. GABA is one of your major inhibitory neurotransmitters and high levels could make you feel tired.

            How long have you been using L-Glutamine?

            Reply
    12. Avatar for Richard Lee SteackerRichard Lee Steacker says

      March 1, 2022 at 12:39 pm

      Thank you David for just an informative and well conveyed article. Much appreciated from someone dealing with chronic tinnitus, insomnia, chronic fatigue and food intolerance. Best, Richard

      Reply
      • Avatar for David TomenDavid Tomen says

        March 1, 2022 at 4:13 pm

        Thank you Richard.

        Reply
    13. Avatar for AleksanderAleksander says

      February 18, 2022 at 5:01 am

      Hi David! If I know nothing about my Gln/Gly(GABA) cycle then it’s not wise to add 5g of L-Glutamine to daily suplementation? Additionaly L-Glutamine can increase my GABA levels right?

      Thank you!

      Reply
      • Avatar for David TomenDavid Tomen says

        February 18, 2022 at 3:49 pm

        Aleksander, the recommended daily dosage of L-glutamine is 2 to 5 grams per day. And it WILL make GABA and then Human Growth Hormone.

        Reply
    14. Avatar for MalikMalik says

      December 8, 2021 at 4:08 am

      Hello David ! I take l glutamine but I feel a little heavy in my head. Is there any alternative to l glutamine? Thanks

      Reply
      • Avatar for David TomenDavid Tomen says

        December 8, 2021 at 3:49 pm

        Malik, the only alternative if GABA. Because L-Glutamine turns into glutamate which turns into GABA and then Human Growth Hormone.

        Reply
    15. Avatar for MalikMalik says

      December 2, 2021 at 10:00 am

      HELLO DAVID! What brand you recommend for standalone l glutamine. Thanks

      Reply
      • Avatar for David TomenDavid Tomen says

        December 4, 2021 at 11:18 am

        https://amzn.to/3Eogo5t

        Reply
    16. Avatar for PaoloPaolo says

      September 19, 2021 at 4:49 pm

      Hi David,
      if i have issues with high glutamate low gaba.
      Do you think it is a good idea to supplement glutamine ? Or do i risk to cause even more excitatory issues ?

      Reply
      • Avatar for David TomenDavid Tomen says

        September 20, 2021 at 2:31 pm

        Paolo, exactly the opposite because you need to have glutamine, glutamate and GABA in balance. Check the 5th paragraph under the “Overview” section above to see how it works and why this balance is so critical. With high glutamate consider supplementing with L-Glutamine and GABA to counter it.

        Reply
    17. Avatar for BarbaraBarbara says

      September 13, 2021 at 7:10 pm

      Hello David
      In the case of headaches caused by not sleeping enought (For dont have enought time to sleep, not for insomnia) or in cases of migraines,
      which nootropics would you recommend? (Alpha Gpc has not helped me)

      -i just received PS from this brand, Its derived from soy. Do you think its a concern?
      or is it good enough?

      Bulk Supplements Phosphatidyl Serine Powder

      -Do you think “Domperidone” is bad to take it a few times a week?

      -If something appears on Drugs.com without interaction, is it completely safe to combine with a nootropic?

      Reply
      • Avatar for David TomenDavid Tomen says

        September 14, 2021 at 4:16 pm

        Barbara, Bulk Supplements is a trustworthy company. But it depends on whether you mind a supplement made from soy rather than sunflower lecithin. I prefer to avoid soy but if all you need is a PS supplement this should work. Just make sure you measure the powder accurately.

        Reply
        • Avatar for BarbaraBarbara says

          September 16, 2021 at 1:07 pm

          Thanks David, Could you help me with the rest of the unanswered questions please thanks for your time

          And What kind of negative effect does soy have compared to supplement made from sunflower lecithin?

          Reply
          • Avatar for David TomenDavid Tomen says

            September 21, 2021 at 6:46 pm

            Barbara, just one example are the Isoflavones which are found in soy are plant estrogens. High levels of estrogen have been linked to an increased risk of breast cancer. Is it worth the risk if you can get a proven safe alternative instead?

            Side effects associated with domperidone include dry mouth, abdominal cramps, diarrhea, nausea, rash, itching, hives, and hyperprolactinemia (the symptoms of which may include breast enlargement, galactorrhea, breast pain/tenderness, gynecomastia, hypogonadism, and menstrual irregularities). And 10–15% of female patients have been reported to experience breast enlargement, breast pain/tenderness, excessive milk production/secretion, and cessation of menstrual cycles with domperidone treatment.

            Reply
    18. Avatar for KenKen says

      August 14, 2021 at 7:00 pm

      Hi David, i am really grateful for all what you are doing by helping many of us out there.
      Currently im taking Gaba 500, is it advisable to also take L-glutomine? Im suffering with work related panic attacks and i have ibs.

      Reply
      • Avatar for David TomenDavid Tomen says

        August 15, 2021 at 4:50 pm

        Ken, if you are dealing with IBS then L-Glutamine is a great idea.

        I suggest you do a search of this website using the search tool right of the top menu on this page and do a search for the keyword phrase “panic attacks”. And see what turns up.

        Reply
        • Avatar for KenKen says

          August 16, 2021 at 8:26 pm

          Thank you David, but can i combine l-glutamine with gava? Thanks again

          Reply
          • Avatar for David TomenDavid Tomen says

            August 18, 2021 at 2:47 pm

            Ken, yes you can use L-Glutamine and GABA the same day.

            Reply
    19. Avatar for salemsalem says

      July 6, 2021 at 3:57 am

      hi david

      can we take g5 glutamine along with 500mg tyrosine ?

      Reply
      • Avatar for David TomenDavid Tomen says

        July 6, 2021 at 5:18 pm

        Salem, 3 grams of L=-Glutamine would be better to start with. And yes it’s fine with L-Tyrosine because glutamine increases GABA and tyrosine increases dopamine.

        Reply
      • Avatar for PhilPhil says

        October 17, 2021 at 5:44 am

        Hi David, I’m interested to test out the GABA/Glutamate balance.

        Is there any recommended steps you would suggest to see if you are depleted in either GABA or glutamate? and I guess then understand the balance between them.

        I’ve had indications that glutamate is low and GABA is high. I’ve just got a 1g pack which I’m yet to try.

        Reply
        • Avatar for David TomenDavid Tomen says

          October 18, 2021 at 2:32 pm

          Phil, if you think glutamate is low the quickest way to increase it is by using L-Glutamine.

          Reply
    20. Avatar for Yash GaikwadYash Gaikwad says

      May 5, 2021 at 12:27 am

      Hello,

      I am taking l-glutamine supplement to fix my leaky gut to clear my psoriasis. But I found out that l-glutamine gets converted to glutamate in our bodies and which is toxic in high ammount to the brain. Please clarify and explain. I greatly appreciate any help.

      Thankyou.

      Reply
      • Avatar for David TomenDavid Tomen says

        May 5, 2021 at 3:59 pm

        Yash, glutamate is only toxic when it gets out of control. Or when your glutamine/glutamate/GABA cycle gets of of whack. You need glutamate for neuron signaling and learning and memory.

        Glutamate can be toxic in for example Huntington’s Disease. But if you are not experiencing gene dysfunction then supplementing with L-Glutamine will help relieve glutamine deficiency, increase beneficial glutamate, GABA and Human Growth Hormone.

        See the “Side Effects” section above so you know the signals to look for in case you thing you are overdoing it with L-Glutamine.

        Reply
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