Just Added

: 1

Shopping Cart
Free UK Delivery On Orders Over £50
L-THEANINE: The Science Behind Stress & Concentration

L-THEANINE: The Science Behind Stress & Concentration

Chad, a formulations chemist writing for Utmost Me, talks us through the science behind how L-Theanine combats stress and anxiety to help improve cognitive performance. Perfect for helping you to perform at your best, even under pressure...

Almost all creatures have an amazingly constructed chunk of tissue embedded within them that acts as the control center to their entire bodies. With billions of neurons making thousands and thousands of neural connections per second all throughout the day, we are forced to admit that the brain is by far one of the most complicated but fascinating storage and processing systems on the planet. As impressive and important as this biological computer seems to be however, it does slow down and has problems at times... especially under times of stress. Interestingly, there just happens to be an amino acid found in nature’s pharmacy that helps to prevent both. Introducing L-Theanine...

The Incredible L-Theanine - What Is It?

L-theanine is the reaction product of when the amino acids glutamate and glutamine come together and get rearranged a bit. This unique amino acid analogue is typically found in plants and some fungal species. It has the ability to cross the blood-brain barrier by itself, a path which not too many biomolecules can transverse, and seems to be able to perform its pharmacological magic directly on target cells (1).

What are the benefits of L-theanine?

Although L-theanine has much research on its ability to directly improve cognitive performance and boost mood in a way similar to that of caffeine (2-4), it primarily is known for its amazing ability to act as a non-drowsy anxiolytic (5). It does this by preventing the brain from “firing up” during times of stress and anxiety, thus allowing to stay calm and the brain to do what it is meant to do with little interruption or distraction. Perfect for stressful times, such as studying or meeting deadlines. It is also by this same mechanism that L-theanine can act as a mild sleep aid.

How does L-theanine work?

Within certain regions of our brain lie glutamate receptors. These are the “doorbells” to certain neural cells, that when pushed will send an excitatory signal to our brains calling for action. L-theanine is very similar in structure to glutamate (the receptor’s primary substrate) that it can actually bind and block glutamate from “ringing the doorbell”. At the same time, L-theanine has the capacity to bind to what are called GABA and glycine receptors (6). These are the “calming” receptors in the brain - sort of opposite to the glutamate receptors. This is why L-theanine acts as a “mixed-action agonist”, giving it a one-two punch against stress and anxiety.

What Is L-theanine used for?

Even though L-theanine does wonders for cognitive performance, it also has been used for:

  • Symptoms of ADHD (Attention Deficit Hyperactive Disorder) (7)
  • Depression (8)
  • Blood pressure (9)
  • Stress and anxiety (10,11) - reduces anxiety to calm the brain to work better under pressure. 

Won't L-theanine make you sleepy?

No. Since L-theanine acts as a mixed-action agonist (as explained earlier) it does not elicit any drowsy side effects. It simply blocks the excitation doorbells in the brain. It does not bind to any “sleepy” doorbells.

Exactly how does L-theanine help me concentrate better?

It is known that our brain does not operate at full capacity while under psychological and physiological stress (12). With that being said, L-theanine exhibits its cognitive prowess by reducing mental excitation during times of stress and anxiety. Remember, an anxious mind is a distracted mind. By calming it, you can concentrate and focus better.

Infographic - L-Theanine for Focus and Concentration

How long does L-theanine last in our bodies? How long does it work for?

This amazing little amino acid has been reported to do its brain-relaxing work just 40 minutes after administration (13), and has a half-life of around an hour to an hour and 15 minutes (14). So, due to its water-solubility, short pharmacokinetic lifespan, and quick action time, L-theanine must be administered more than just once per day.

What is the usual dosage for L-Theanine?

Although dosages in clinical studies underwent by using laboratory animals were extremely high in order to elicit favorable data, typical daily dosages for humans to improve cognitive performance range from 100mg – 400mg/day (15,16). 

Are there any side effects to L-theanine?

Although there are side effects with everything we put into our bodies, with the exception of some research in which mega-dosing in mice was observed (17), L-theanine typically does not have any known side effects when administered in safe doses, barring any pre-existing medical conditions or concomitant medication of the user.

Can L-Theanine be taken with other supplements to enhance its effectiveness?

L-theanine can absolutely be stacked with other supplements such as caffeine, certain minerals, amino acids, and certain B-vitamins and shows beneficial results regarding working memory and concentration (18,19,20). Considering this, what helps even more are products that already contain these stacks, products such as Neuro Focus Plus. These products take the guesswork out of trying to figure out how much of each nutrient to stack, as well as having to take the time to go out and buy them separately.

Neuro Focus Plus Ingredients

What is the best way to take L-Theanine?

One of the best ways to take L-theanine, along with most amino acids, is on an empty stomach and in conjunction with certain extracts, namely black pepper. Since amino acids like to compete for absorption with other amino acids, especially the ones within their same class, L-theanine is best absorbed and translocated when taken separately from food. Since lecithin and black pepper actually enhance its absorption (21, 22) however, it is a good idea to include these when taking L-theanine.


So now that we have a clearer understanding of this amazing little neurochemical and what it can do, if and when supplementation with L-theanine is at hand we now have a better understanding of how to take it, what to take it with, and what other nutrients increase its effectiveness.


Visit the Utmost Me focus blog for more helpful advice and tricks to help you concentrate more, focus clearly and reach your full potential.

The information shared in Utmost Me articles is not intended to replace qualified health care professional advice and is not intended as medical advice. Always seek the advice of your GP or other qualified health provider with any questions you may have regarding any medical condition.


1. Yokogoshi, Hidehiko; Kobayashi, Miki; Mochizuki, Mikiko; Terashima, Takehiko (1998). "Effect of theanine, γ-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats". Neurochemical Research. 23 (5): 667–73.
2. Haskell, Crystal F.; Kennedy, David O.; Milne, Anthea L.; Wesnes, Keith A.; Scholey, Andrew B. (2008). "The effects of l-theanine, caffeine and their combination on cognition and mood". Biological Psychology. 77 (2): 113–22.
3. Owen, Gail N.; Parnell, Holly; De Bruin, Eveline A.; Rycroft, Jane A. (2008). "The combined effects of L-theanine and caffeine on cognitive performance and mood". Nutritional Neuroscience. 11 (4): 193–8.
4. Einöther, Suzanne J.L.; Martens, Vanessa E.G.; Rycroft, Jane A.; De Bruin, Eveline A. (2010). "L-Theanine and caffeine improve task switching but not intersensory attention or subjective alertness". Appetite. 54 (2): 406–9.
5. Kimura, Kenta; Ozeki, Makoto; Juneja, Lekh Raj; Ohira, Hideki (2007). "L-Theanine reduces psychological and physiological stress responses". Biological Psychology. 74 (1): 39–45.
6. Kakuda T (2011). "Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction". Pharmacol. Res. 64 (2): 162–8.
7. Lyon, Michael R.; Kapoor, Mahendra P.; Juneja, Lekh R. (2011). "The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial" (PDF). Alternative Medicine Review. 16 (4): 348–54.
8. Hidese S et al., Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr. 2017 Apr;29(2):72-79.
9. Yoto A, Motoki M, Murao S, Yokogoshi H., Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012 Oct 29;31:28.
10. Ogawa S et al., Effects of L-theanine on anxiety-like behavior, cerebrospinal fluid amino acid profile, and hippocampal activity in Wistar Kyoto rats. Psychopharmacology(Berl). 2018 Jan;235(1):37-45.
11. White DJ et al., Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial. Nutrients. 2016 Jan 19;8(1).
12. Kindermann NK, Werner NS., The impact of cardiac perception on emotion experience and cognitive performance under mental stress. J Behav Med. 2014 Dec;37(6):1145-54.
13. Juneja LR, Chu DC, Okubo T, Nagato Y, Yokogoshi H. L-theanine–a unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Technol. 1999;10:199–204.
14. Van der Pijl PC, Chen L, Mulder TPJ. Human disposition of l-theanine in tea or aqueous solution. J Funct Foods. 2010;2:239–244.
15. https://www.webmd.com/vitamins/ai/ingredientmono-1053/theanine 
16. Jackson Williams et al.,l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. Beverages2016, 2(2), 13.
17. Yu XC, Wu BL, Gao JC, Yang W., Theanine enhanced both the toxicity of strychnine and anticonvulsion of pentobarbital sodium. Drug Chem Toxicol. 2016;39(2):217-23.
18. Bryan, Janet (2008). "Psychological effects of dietary components of tea: Caffeine and L-theanine". Nutrition Reviews. 66 (2): 82–90.
19. Harris R.Lieberman, Tyrosine and Stress: Human and Animal Studies. Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Washington (DC): National Academies Press (US); 1994.
20. David O. Kennedy, B Vitamins and the Brain: Mechanisms, Dose and Efficacy—A Review. Nutrients. 2016 Feb; 8(2): 68.
21. Kritika Kesarwani, Rajiv Gupta, Bioavailability enhancers of herbal origin: An overview. Asian Pac J Trop Biomed. 2013 Apr; 3(4): 253–266.
22. Han HK., The effects of black pepper on the intestinal absorption and hepatic metabolism of drugs. Expert Opin Drug Metab Toxicol. 2011 Jun;7(6):721-9.

NEW Nootropic Brain Vitamins

Brain Vitamins & Natural Nootropics

Focus, Concentration and Memory Blend with L-Tyrosine + Rhodiola + Turmeric [Curcumin Focus] + Caffeine + L-Theanine to enhace Alpha Brain Waves for a cognitive boost.

Shop Now

Leave a comment

your email address will not be published

How much is:

Please note, comments must be approved before they are published

Ready To Be More
get neuro focus plus