Theanine: a 4000 Year Old Mind-Hack

by Tony Gebely 36

Monks have been drinking tea for thousands of years to maintain a state of “mindful alertness” during long periods of meditation. But only in the last few years have studies shed light on why tea has this effect on the mind. The two elements responsible for this are caffeine and L-theanine, and it is the combination of the two that makes tea unique from any other drink.

Spare Me the Science: What L-theanine and Caffeine can do for the Mind

  • Promote a mindful state of relaxation
  • Increase our ability to multi-task, and multi-task well
  • Increase speed of perception
  • Increase performance under stress
  • Improve learning ability and concentration
  • Decrease anxiety
  • Reduce task-induced fatigue

The Science

L-theanine is an amino acid responsible for increasing alpha brain wave activity, which promotes relaxation. In concert with the stimulant caffeine, this allows tea to induce a feeling of increased concentration over a longer period of time, compared to caffeine alone. Some tea merchants will tell you that tea “releases” its caffeine into the body more slowly than coffee, but in actuality, the effects of caffeine are being moderated by L-theanine.

Recent studies have shown that tea “. . . taken throughout the day can significantly benefit speed of perception and more consistent levels of simple task performance. L-theanine appears to antagonize the stimulatory effects of caffeine by decreasing seratonin levels that have been artifically elevated by caffeine”  [1]. As a result, the bod sustains a feeling of alertness that cannot be obtained by the caffeine in coffee or soda.

Studies have also shown that there are added benefits to tea, besides alertness. In a paper by Eschenauer and Sweet, it was concluded that “increased alpha activity in the brain induced by L-theanine has been associated with increased creativity, increased performance under stress, and improved learning and concentration as well as decreased anxiety.” [2] A 2001 study suggests that the combination of L-theanine and caffeine “improves the ability to multi-task and reduces task-induced fatigue,” [3] which is something we can all benefit from.

L-theanine is seldom found anywhere in nature other than tea,  a single species of mushroom, and guayusa which is a holly species typically processed and drunk as a tisane. It is “synthesized in the roots and concentrates in the leaves, where sunlight converts [L-theanine] to polyphenols,” [4] In other words, shade-grown teas like Gyokuro, a Japanese green tea, have higher concentrations of L-theanine because the amino acid is not converted into polyphenols as much as tea leaves that are exposed to full sun.


Due to the unique combination of L-theanine and caffeine found in tea, there are many reasons as to why this can be another alternative to coffee and soda, especially when looking for a jump-start to the day, or a way to maintain concentration for hours of coding and/or studying. It is best to experiment with different teas and find out how each tea affects you. A good starting point to discover different and appealing teas is the “Hacker’s Guide to Tea.

  1. [1]Bryan, Janet. “Psychological Effects of Dietary Components of Tea: Caffeine and L-theanine.” Nutrition Reviews 66.2 (2008): 82-90. Web.
  2. [2]Eschenauer G, Sweet BV. Pharmacology and Therapeutic Uses of Theanine. AM J Health-Sys Ph 2006; 63-26-30.
  3. [3]Giesbrecht, T., J. A. Rycroft, M. J. Rowson, and E. A. De Bruin. “The Combination of L-theanine and Caffeine Improves Cognitive Per…” Nutritional Neuroscience 13.6 (2010): 283-90. Web.
  4. [4]“L-Theanine.” Alternative Medicine Review 10.2 (2005): 136-37. Print.

Tony Gebely

Tony has been studying tea for over ten years and has traveled to many tea producing regions throughout Asia. His book, "Tea: A User's Guide" is available now.

Comments (36)

  1. Hi I suffer from palpitations and my Dr has told me to avoid caffeine …. thus I only drink decaff coffee and decaff tea. Does L-theanine mean I can drink non decaff tea
    Yours hopefully

  2. Hey,
    thank you for this article.
    I have a question, maybe you will be able to answer it. Don’t know, if there are any studies made in this direction, but I’m really interested in how the content of L-theanine depends on brewing process. Do you know, when the most part of it is released? By preparing a calming or stimulating green tea? Or maybe a between them two?

  3. I’ve been drinking Puerh and other lower level l-theanine content tea for ease of migraine and fibromyalgia symptoms for over a year. Why not green tea? The caffeine caffeine level would be excessive. I dose at least 40-60 oz. of tea daily and find the ritual and continual low dose has kept minor mood fluctuations and migraines at bay. I had one big pain crisis in two years which is better than most people who take drugs!
    The reason I’m mentioning all this is because green tea isn’t the only delivery system and caffeine sensitive people may find shu puerh in particular more soothing to the stomach. All this is of course my own opinion based on my experience and success.

    1. Bonnie, I just wanted to mention that I recently found out that free glutamate was the cause of my migraines, which were ruining my life, by the way. Coincidentally, I take L-theanine capsules (also found in green tea) to combat it. I also really have to be careful to avoid dietary glutamate. “Natural flavors” is a biggy for me. I avoid it like the plague, but if i get a hold of some, L-theanine will prevent the migraine from going full-bore. Hope you see this and it helps.

  4. Dude I like the look of your site, but you REALLY need to make the font of this site both darker and larger. I had to zoom in to read, and still had to peer my eyes.

  5. L Theanine can also be found in Bay Bolete mushroom and in guayusa, an Ecuadorian relative of Mate. The pill form may be of limited value as some studies have indicated it works best in conjunction with the catechins in tea.

  6. why did you illustrate this post with tibetan monks? aside from the fact they are not meditating here, they do not drink matcha tea, and typically drink the cheapest ctc tea boiled with milk, butter and salt (which is what they are serving)

    1. because the title is 4000 year old mind-hack. monks began drinking tea to stay alert during long periods of meditation.

      1. I understand that, what I was asking is why did you illustrate the article with a group that does not use tea as a stimulant? your reference it to tao or zen monks. big difference, your illustration may as well have been of catholic monks.

        1. I was looking to use a photo of monks drinking tea. Any monk drinking tea illustrates my point. L-Theanine and caffeine occur in all teas.

          1. He doesn’t get enough attention in the real world, so he’s reduced to criticizing photo choices as a fill in on the internet. Gold star monkey. No one still likes you.

    2. Why did you have to be a negative Nancy about his choice of an illustration which carries validity in relation to the point and context? Perhaps, you should have drank some tea, mulled over such a malicious thought before bringing it into observable reality, and settled upon refraining from intended destruction.

      1. Perhaps you should have taken a moment yourself or read the thread explaining the motivation behind the valid comment about the illustration being incongruous with the facts in the post before making such an aggressive and judgmental comment. The post discusses Japanese teas and tradition, not Tibetan. You may not find it significant, but a Tibetan Buddhist or Zen Buddhist would recognize the vast difference between the traditions, nationalities and reason why tea is consumed.

  7. A great article, and if you are looking for the highest l-theanine and caffeine combined levels you need matcha grren tea. Matcha is tencha green tea- meaning shade grown. tencha leaves are also used to make Gyokuru tea, also high is L-Theanine. The difference with matcha (meaning literally powdered tea) is you consume the entire leaf, thus benefiting from the chlorophyll and other goodies that would normally end up in the garbage. 1st Harvest or Ceremonial matcha has the highest L-theanine and the highest antioxidants. Matcha tea is also loaded with EGCG EpiGalloCatechin Gallate . This is super concentrated in Matcha tea over 100 x more than regular green tea, and is getting known for it’s powerful anti-cancer qualities.

    1. Thanks for this helpful info.

      I am concerned about the radiation found in Japanese teas from the 2011 Fukushima nuclear disaster.

      Are there any high Theanine/ caffine teas that are not from Japan ie Brazil. I like the vegetal taste in addition to the well being of the higher end Senchas.

      Many thanks,
      Tea fan

  8. Thank you very much for this interesting article! Isn’t great that those two elements are found in a as good tasting and aromatic plant composed of hundreds of different organoleptic elements?!? Tea is just so fantastic!
    If Japanese shaded cultures like Gyokuro, Kabusecha and Matcha (Tencha) have a higher level of L-Theanine, I imagine that high-mountain Oolongs that are shaded by mist have a higher level of it as well… That would explain the good feeling they offer along the essential oils they also contain.

  9. Tony, thanks for the great article. Do you know if the amount of L-Theanine vary with different types of tea based on processing, fermentaion or?

  10. Great post, really interesting.
    I recently started drinking green tea regularly throughout the day and definitely have noticed an improvement in the way I focus. Not just that but energy wise as well, a lot different from coffee because I dont feel tired a few hours later.

  11. Love Oolong Tea, drink it a few times a day! Am I now a monk?

  12. Tony, will you honor this discount at your brick and mortar store. I was thinking about coming this weekend.

    1. I don’t have one yet 🙁

      1. Well that’s disappointing. I saw the address on your site and assumed it was a store. Well guess it’s good I found out before I took a trip there. I could have ended up very confused.

        1. We do hold tastings periodically at our warehouse. Are you close by?

          1. Yeah, practically within walking distance. Do you think you’d be willing to do orders on your site for pick up? It seems silly to ship when I’m within 20 minutes of the warehouse.

  13. Like caffeine L-Theanine goes only in the first infusion on the tea or if we refile with hot water more L-Theamine come from the leaves?

  14. I have been using this stuff for years, it works great, but forget about
    trying to get it from tea, the best way I have found is to buy it in pill
    form, that way you can get a full dose and you can take it with
    coffee instead of just tea.

    I get it on amazon.

    1. Or the best of both worlds – wash down a couple of l-theanine capsules with a cup of good tea!

  15. Wow – I need to go through my tea drawer and start testing! Thanks for the info. It sounds like I need to get an electric kettle for my workshop, now.

  16. More research required into hot or ices & black or green. That’ll be a fun experiment.

  17. I think it is an excellent benefit of tea, but I just wonder how much good a pill form does. I am a bit skeptical of isolating ingredients and think you are getting the same effect. Their could be other cofactors of tea that would help the absorption of l-theanine that haven’t been discovered yet.

  18. To Kevin’s point: my nutritionist recommended it and I’ve been taking it in pill form for a bit. It does hit faster and doesn’t give me a crash, but I prefer taking it in a hot beverage (because it tastes better and because I love drinking tea anyway). But I do keep a few around for an afternoon study jam.

    Thanks for this article! I only just figured out that the L-Theanine I was taking in pill form is also in my favorite drink!

  19. Great article.

    I wrote a response here:

    Also I’m interested in the name of the mushroom that has significant levels of L-Theanine.

    Thanks again for the great read!

    1. a weird blueish mushroom called the bay boleet, which has these little holes instead of gills

  20. Thanks for the info. Now I’m wondering which teas have the strongest caffeine and l-theanine.

    1. I can sell you some with highest concentrations for $100 an ounce. Alternatively you can just drink too cups.

      1. I laughed out loud at this solution and comment. (Spelling error: Two)

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