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L-Theanine Dosage: How Much Should You Take?

One of the top questions about this great supplement is: 'what is the ideal L-Theanine dosage'? L-Theanine is one of our best active amino acids, helping to promote a calm, relaxed mood without drowsiness. People often use L-Theanine with caffeine because of the great relationship between these two substances.


In this article, we’ll explore the correct L-Theanine dosage: how to take and when to take it. We also look at some L-Theanine stacks and how much L-Theanine you’ll find in tea. This article is great for anybody who would like to start taking L-Theanine supplement!

woman relaxing with some L-Theanine supplement

1.    What is the ideal L-Theanine dosage?

According to Examine.com - a great resource for scientific information about supplements - the L-Theanine dosage that is used in most studies is around 100-200 mg once or twice daily.[1]


Some people choose to use a higher L-Theanine dosage, without any negative adverse effects. At higher doses, your body will use much of the L-Theanine to build more proteins. We do not recommend exceeding the recommended dosage. Check out our Ultimate Guide to L-theanine for more information!


2.    How much L-Theanine is in Tea?

Many people wonder about how much L-Theanine is found in tea! The amount of L-Theanine in your tea depends entirely on the strength and variety of tea that you use. However, scientists estimate that one cup of regular black tea usually contains an L-Theanine dosage of around 20 mg.[2]


If you want to reach the recommended dosage for L-Theanine benefits you’d need to drink at least 5 – 10 cups of strong black tea in row. This is why we recommend using a high quality dietary L-Theanine supplement in order to feel the great benefits of this wonderful substance.


3.    When to take L-Theanine

The time that you choose take L-Theanine depends on what kind of benefit you’d like to experience. L-Theanine is mostly used as a calming supplement. It may also help to promote healthy sleeping patterns. L-Theanine also goes really well with caffeine.[3] If you’re looking for a supplement to help reduce stress, you may be wondering about the optimum L-Theanine dosage to take in the morning.


man relaxing in hamock with l-theanine You can take l-theanine at any point in the day where you'd like to feel relaxed

We’d recommend a dosage of 100 – 200 mg pure L-Theanine at any point in the day that you’d like to feel more relaxed. Many people choose to take an L-Theanine supplement in the morning with a cup of coffee, because of the syngeristic relationship between L-Theanine and caffeine.


If you’re wondering about how much L-Theanine to take for sleep, we’d recommend a slightly higher dosage of around 200 mg around 1 hour before bed. Scientists believe that the sleep-promoting effects of l-theanine are related to its ability to help your body manage stress.[4]


4.    How to use L-Theanine in a stack


People use l-theanine in stacks very often. It is a great supplement to use in supplement stacks because of its safe, natural origin and the fact that it has a synergistic relationship with many substances.


The Top 3 L-Theanine stacks are:


  1. L-Theanine with Caffeine

This is definitely the most common L-Theanine stack. People often wonder about how much L-Theanine to use with caffeine. A regular L-Theanine dosage of around 100 – 200 mg with a cup of coffee makes a great supplement stack for improving energy, focus and mood. Many users claim that L-Theaine helps to take the edge off from caffeine.[5]


L-trytophan vs 5-htp Liftmode's 5-HTP, 98+% pure
  1. L-theanine with 5-HTP

Another great stack is L-Theanine with 5-HTP. This stack is great for relaxation and improving mood.


The mood-lifting benefits of 5-HTP are unparalleled with other natural dietary supplements.[6] Combining this with L-Theanine allows you to feel the relaxing effects of L-Theanine with a great mood-boost!


  1. L-theanine with Green Tea Extract

This top L-Theanine stack is the ultimate tea extract stack! It gives you the calming and relaxing benefits of pure L-Theanine, combined with the health-promoting effects of catechins and polyphenols from green tea.[7]


5.    What about L-Theanine side effects?

In at least one study, researchers noted that the upper limit for feeling adverse effects was above 2000 mg/kg bodyweight per day.[8]


This means that, for an 80kg (176lb) person, the limit for feeling adverse effects would be over 160 grams in one day. However, please remember that each person’s metabolism is different, and some people may be more sensitive to the effects of supplements than others.



woman meditating on the beach, calm L-theanine is great for supporting a calm, relaxed mood

In conclusion, L-Theanine is a wonderful dietary supplement to help promote a calm, relaxed mood. People often wonder about the ideal L-Theanine dosage: the recommended amount is 100 – 200 mg once or twice daily. L-theanine is also great when taken in supplement stacks. It has a synergistic relationship with a number of other supplements.


You can take L-Theanine in the evening before sleep, in the morning before work, or at any point in the day when you’d like to feel more relaxed. L-theanine goes really well with caffeine to produce calming effects with focus and energy.




[1] L-theanine, Examine.com, retrieved on November 1, 2016

[2] L-theanine, a natural constituent in tea, and its effect on mental state, AC Nobre et al., Asia Pac J Clin Nutr. 2008;17 Suppl 1:167-8.

[3] The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness, T Giesbrecht et al., Nutr Neurosci. 2010 Dec;13(6):283-90.

[4] L-Theanine reduces psychological and physiological stress responses, K Kimura et al., Biol Psychol. 2007 Jan;74(1):39-45. Epub 2006 Aug 22.

[5] The effects of l-theanine, caffeine and their combination on cognition and mood, CF Haskell et al., Biological Psychology, Volume 77, Issue 2, February 2008, Pages 113–122

[6] 5-HTP efficacy and contraindications, M Hinz et al., Neuropsychiatr Dis Treat. 2012; 8: 323–328, Published online 2012 Jul 19.

[7] Beneficial effects of green tea: A literature review, SM Chacko et al., Chin Med. 2010; 5: 13., Published online 2010 Apr 6

[8] In Search of a Safe Natural Sleep Aid, TP Rao et al., J Am Coll Nutr. 2015;34(5):436-47.