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4.6 out of 5 based on 5 customer ratings
(5 customer reviews)
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L-theanine is a well-known non-essential amino acid. It is deemed unimportant in the human diet however, supplementing with this substance have been identified to promote numerous benefits to the body. Structurally, L-theanine is similar to that of glutamate, glutamine and gamma aminobutyric acid (GABA). In addition to this, it has the ability to reach the brain through easily crossing the blood brain barrier within 30 minutes following oral intake [1].

  • Overview
    Quantity 100g = 100,000mg


    L-theanine is naturally a rare compound. It can only be seen on Camellia species (e.g. camellia sinensis, camellia sasanqua & camellia japonica leaves) and on some edible boletes mushroom (Xerocomus badius). It is also the predominant amino acid found on tea which is thought to give flavor to tea leaves. As a matter of fact, it constitutes 1 to 2% of tea’s dry weight corresponding to 25 to 60 mg of L-theanine in every 200 ml serving [2]. For this reason, one may only be able to gain a therapeutic dose of L-theanine with increased intake of green tea.

    Several properties have been associated with L-theanine intake. One of its most essential and otherwise primary characteristic includes its ability to promote relaxation without causing sedation. Numerous studies have also discovered that it may be effective in promoting focus and attention, sleep as well as improved stress perception [2]. The ability of L-theanine to promote attention and relaxation without sedative effects makes it an ideal supplement when used with other stimulants. For instance, combining L-theanine with caffeine has been noted on some studies to produce a synergistic result in increasing attention and cognition [3] [4]. Another benefit associated with L-theanine is its ability to support cardiovascular health. L-theanine is thought to positively influence nitric oxide regulation.

    Key Findings

    Several key findings from studies identified the following benefits of L-theanine supplementation:

    • Notably increases relaxation without producing sedation occurring within 30 minutes of oral ingestion [1]
    • Possible ability to decrease anxiety [5] [6]
    • Improve sleep quality in individuals diagnosed with attention deficit hyperactivity disorder or ADHD [7]
    • Prevents the negative effects of stress towards memory [8]
    • Improves mental alertness and arousal [1]
    • Protect neuronal cells through its neuroprotective properties [9]
  • Description

    Product Description

    Please note: This article is for informational purposes only. Only buy L-Theanine for research. We do not encourage intake of L-Theanine or any other nootropic substance listed/discussed/sold on this site.


    L-theanine has been thought to cross the blood brain barrier, directly exerting its effects towards the brain within 30 minutes of ingestion. Randomized controlled trials revealed that in higher doses, L-theanine significantly increased the power of alpha frequency band across the occipital and parietal areas of the brain as seen in electroencephalogram. These studies have also revealed that L-theanine is only effective amongst individuals with high levels of anxiety [1].

    Its ability to decrease anxiety was also revealed in a study involving 40 patients diagnosed with schizoaffective and schizophrenic disorder. This clinical research showed that alongside antipsychotic therapy, a significant amelioration of anxiety symptoms were seen amongst the study subjects [6]. Four separate trials performed on 12 participants in another study revealed similar results. In this specific study, oral intake of L-theanine has been identified to produce anti-stress effects through preventing cortical neuron excitation [5].

    A randomized, controlled clinical trial performed on boys with ADHD demonstrated efficiency and safety of L-theanine in promoting quality of sleep. Sleep problems is a comorbidity of ADHD and may even be a cause of childhood ADHD. Henceforth, L-theanine may be an important and effective supplement to improve sleep quality amongst this population [7]. Nonetheless, long-term and larger studies are needed to prove that this compound is really beneficial in improving sleep.

    Several other studies have also shown the ability of L-theanine to prevent the effects of stress in memory. In an animal study, it was revealed that theanine intake decreases effects of induced stress amongst rats through inhibiting specific receptor agonists in the hippocampus. Primarily, theanine is thought to modify the secretion of corticosteroid in the brain promoting such preventive effect in memory [8]. Its neuroprotective properties on the other hand are related to its ability to suppress the negative effects of glutamic acid. It may also prevent the oxidation of low density lipoprotein and act as a scavenger of harmful substances in the brain thereby inhibiting occurrence of ischemic cerebrovascular disease [9].

    How L-Theanine works and why you should buy L-Theanine

    L-theanine is able to produce its effects through effectively crossing the blood brain barrier (BBB). For this reason, concentrations of this compound are significantly increased within an hour of oral intake. It produces its peak effects approximately 5 hours after intake. It is then eliminated after 24 hours. Studies revealed that L-theanine increase in the brain is primarily seen in the hippocampus. Its mechanism of action on the other hand is related to its ability to improve alpha waves or a-waves amongst healthy individuals. Its benefits however are more prominent amongst people with higher anxiety and stress baseline. Another reason for to buy L-Theanine is that these alpha waves are essential in the promotion of focus, attention, relaxation, arousal and alertness [8] [10] [11] [12].

  • Reviews (5)
    4.60 out of 5

    5 reviews for L-Theanine

    1. 4 out of 5


      I have been taking this as a recommendation from friends. And I must say, it really helps me focus. Not to mention that it also helps my occasional anxiety fits.

    2. 5 out of 5


      Tried this at the start of my day and ended up getting lots of work done. Really helps me a lot, especially on my busy days when I have to finish a lot of work. Thanks for the product!

    3. 4 out of 5


      I usually take this with caffeine and it works great for me. Really helps alleviate my feelings of depression which sometimes come upon me. It helps me feel like a normal person.

    4. 5 out of 5


      This is really a life-saver for me! Was able to close a deal in my work because of the calm and focus that it gave me after I took in a pill beforehand. It really calmed me down and I was able to present fluently.

    5. 5 out of 5


      I’ve been taking this for over a week now. As a background, I am a huge caffeine user, so the idea of taking this was quite attractive to me after hearing so many others doing caffeine and l-theanine together. My experience from this is that it really gives me a clean and natural focus which I really need to complete my day’s work.

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  • References

    [1] https://www.ncbi.nlm.nih.gov/pubmed/17182482

    [2] https://www.ncbi.nlm.nih.gov/pubmed/18296328

    [3] https://www.ncbi.nlm.nih.gov/pubmed/21040626

    [4] https://jn.nutrition.org/content/138/8/1572S.long

    [5] https://www.ncbi.nlm.nih.gov/pubmed/16930802

    [6] https://www.ncbi.nlm.nih.gov/pubmed/21208586

    [7] https://www.ncbi.nlm.nih.gov/pubmed/22214254

    [8] https://www.ncbi.nlm.nih.gov/pubmed/23458739

    [9] https://www.ncbi.nlm.nih.gov/pubmed/12499631

    [10] https://www.ncbi.nlm.nih.gov/pubmed/9566605

    [11] https://www.ncbi.nlm.nih.gov/pubmed/4397636

    [12] https://www.ncbi.nlm.nih.gov/pubmed/8242688

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