What is L-Theanine? An Unmatched Focus Booster When Paired With One Ingredient

If you are a tea lover, chances are that you may be familiar with a vital ingredient called L-Theanine. This amino acid has a plethora of health benefits and can be found in green or black tea as well as various mushrooms.

L-theanine has quite the reputation as a stress reducer, focus increaser, and sleep improver. If that’s not good enough for you, when mixed with one simple ingredient, the benefits of L-theanine get even greater! In this article, we’re going to dive through the research and explain the benefits of this amazing amino acid in plain English.

What Is L-Theanine?

L-theanine in capsule and powder form

L-Theanine is a non-protein amino acid similar in properties to glutamate, a naturally occurring amino acid. The human body doesn’t produce L-Theanine; it is derived from plant sources such as black and green tea leaves as well as some mushrooms.

L-Theanine has been shown to increase the release of some brain chemicals like dopamine, serotonin, and GABA (gamma-aminobutyric acid). Any change in these chemicals will directly affect your stress levels or mood.

What Is  L-Theanine Used For?

L-Theanine is mainly used for reducing anxiety and stress levels. Although the compound isn’t a sedative, many people have been using it to improve sleep quality. It’s also common that people who consume L-theanine and reap its benefits are doing so unknowingly. Most tea contains L-theanine and green tea generally contains the most, especially matcha.[8]

The Benefits of L-Theanine and the Research Behind It

There’s research that supports L-Theanine improving attention and reaction times as well as benefiting brain function and focus span[4].

On another note, L-Theanine might be your next secret weapon for better sleep.

Several pieces of evidence suggest that L-Theanine-induced sleep is peaceful and doesn’t promote drowsiness and fatigue, unlike other sleep inducers, such as Benadryl or Melatonin[2]. Sleep inducers tend to be sedatives and could cause addiction, drowsiness the next day, headaches, or nausea. Since L-theanine is not a sedative and instead improves sleep through a process called anxiolysis, it’s a perfectly safe and natural sleep aid.[10]

It has been observed that L-Theanine can reduce anxiety, which indirectly improves the overall quality of sleep[3].

One study from Frontiers in Nutrition showed that this lovely bio-chemical compound has multiple health benefits that include anti-inflammatory and antioxidative properties, liver and kidney protection, as well as positive improvement on cardiovascular health[1].

A study published in the journal ‘Beverages’ has stated that L-Theanine can resolve respiratory tract infections and improve many other human health conditions.These include reduced cardiovascular attacks, maintenance of normal blood pressure, and healthy immune function[5].

How and When To Take L-Theanine and in What Amount?

The quantity of L-Theanine depends greatly on what you take it for. According to research, you can safely consume around 250mg of L-Theanine daily[5].              

However, if you want to stay alert, the combination of L-Theanine and caffeine will work best. On the other hand, you can try L-Theanine and ashwagandha tea if your goal is to relieve stress or fall asleep.

Did you know you could consume L-Theanine and 13 other superfoods in one amazing bed time tea?

While black and green teas certainly do contain L-Theanine, they could be greatly enhanced with the addition of several other highly healthy ingredients. Not to mention, if you’re looking to wind down and get good sleep, the caffeine in green tea makes it a no no! MoonBrew is superfood tea designed to give you the best night of rest you’ve ever had. Fall asleep faster and feel well rested and energetic the next day. Simply mix our NoonBrew powder with water and in seconds you have a delicious beverage that contains L-Theanine and 13 other superfoods (such as lavender, jujube seed, spearmint, reishi, chamomile, and turkey tail mushrooms). Enjoy it hot or cold!

L-Theanine is perfectly safe and there are not any directly linked side effects from taking it.[7] There is no evident research on whether L-Theanine is safe for pregnant women or not. But to remain on the safer side, it is suggested that pregnant or lactating ladies should avoid its consumption. If you have questions about if L-Theanine is safe for you, we always recommend consulting with a physician over your concerns.

Try Mixing This One Ingredient With L-Theanine For Deep Focus

If you’re looking for the perfect duo to keep you focused throughout the day, consider having L-theanine with caffeine. L-theanine and caffeine together has the potential to enhance brain function.[6]

These two ingredients have a synergistic effect on each other, giving you more energy and more focus. Better yet, some of the unfortunate side effects of caffeine consumption are cancelled out thanks to the L-theanine.[9]

One study from Northumbria University took a group of 24 people, half being regular consumers of caffeine and half not.[9] Over time, they experimented giving them caffeine alone as well as caffeine with L-theanine. They discovered that the negative effects of caffeine relating to cognitive function and mood were gone when caffeine was consumed with L-theanine. There was better cognitive function in general due to the increased cerebral bloodflow..

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Adding L-theanine to your diet could potentially reduce your anxiety, improve your sleep, and give you an attention boost to keep you going. It’s safe and naturally found in tea. If you’re looking to improve your focus, L-theanine and caffeine are the match made in heaven you are looking for.


  1. Li M, Liu H, Wu D, Kenaan A, Geng F, Li H et al. L-Theanine: A Unique Functional Amino Acid in Tea (Camellia sinensis L.) With Multiple Health Benefits and Food Applications. Frontiers in Nutrition. 2022;9.
  2. Rao T, Ozeki M, Juneja L. In Search of a Safe Natural Sleep Aid. Journal of the American College of Nutrition. 2015;34(5):436-447.
  3. Ritsner M, Miodownik C, Ratner Y, Shleifer T, Mar M, Pintov L et al. L-Theanine Relieves Positive, Activation, and Anxiety Symptoms in Patients With Schizophrenia and Schizoaffective Disorder. The Journal of Clinical Psychiatry. 2010;72(01):34-42.
  4. Higashiyama A, Htay H, Ozeki M, Juneja L, Kapoor M. Effects of l-theanine on attention and reaction time response. Journal of Functional Foods. 2011;3(3):171-178.
  5. Williams J, Kellett J, Roach P, McKune A, Mellor D, Thomas J et al. l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. Beverages. 2016;2(2):13.
  6. Owen GN;Parnell H;De Bruin EA;Rycroft JA; “The Combined Effects of L-Theanine and Caffeine on Cognitive Performance and Mood.” Nutritional Neuroscience, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/18681988/.
  7. Mehta, Foram. “What You Should Know about the Benefits and Risks of L-Theanine.” Healthline, Healthline Media, 20 Jan. 2021, https://www.healthline.com/health/l-theanine#risks-and-side-effects.
  8. Boros, Klára, et al. “Theanine and Caffeine Content of Infusions Prepared from Commercial Tea Samples.” Pharmacognosy Magazine, Medknow Publications & Media Pvt Ltd, 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4787341/.
  9. Dodd, F L, et al. “A Double-Blind, Placebo-Controlled Study Evaluating the Effects of Caffeine and L-Theanine Both Alone and in Combination on Cerebral Blood Flow, Cognition and Mood .” Psychopharmacology, Springer Berlin Heidelberg, July 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4480845/.
  10. Rao TP, Ozeki M, Juneja LR. In Search of a Safe Natural Sleep Aid. J Am Coll Nutr. 2015;34(5):436-47. doi: 10.1080/07315724.2014.926153. Epub 2015 Mar 11. PMID: 25759004.

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