Caffeine + Theanine

(Last Updated On: February 21, 2019)


I’m sure many of you reading this have heard of this combination before, as it’s a fairly popular one among the nootropics community. There is an increasing body of literature which demonstrates caffeine as a nootropic on its own right1https://content.iospress.com/articles/journal-of-alzheimers-disease/jad0913842https://content.iospress.com/articles/journal-of-alzheimers-disease/jad111982, but is enhanced when taken with l-theanine.

When caffeine is taken with l-theanine, it is a completely different beast. Caffeine, as most of you are no doubt aware, is a stimulant found in many beverages, most notably coffee, which is used for it’s stimulatory properties.

While caffeine by itself does not have quite the same effect as a cup of coffee, it is still an effective stimulant on its own. Caffeine has a rather unique pharmacological profile – one of it’s primary MoA’s is antagonizing the neurotransmitter adenosine. Caffeine does this by blocking adenosine receptors, thereby preventing adenosine from getting absorbed into them3https://www.ncbi.nlm.nih.gov/pubmed/20164566.

Adenosine is a neurotransmitter which builds up over the course of the day and is used to signal to our body that we are tired4https://www.sciencedirect.com/science/article/pii/S030100820400125X. By preventing these receptors from binding adenosine, this has the effect that we all cherish: feeling more awake and alert in times where we may otherwise feel groggy and sluggish.

One of the common side effects of caffeine is anxiety and jitteriness. Caffeine is not particularly effective for concentration or focus overall, and in fact too much caffeine can be counterproductive as it can cause too much stimulation.

This effect is known as the Yerkes-Dodson Law5https://link.springer.com/referenceworkentry/10.1007%2F978-0-387-79948-3_1340, and can be applied to just about every situation, and is especially relevant with the use of stimulants such as caffeine.


Yerkes-Dodson Law


This is where l-theanine comes in. L-theanine is a naturally occurring analogue of the amino acid glutamate, and is found most commonly in teas, particularly black tea.

L-theanine is effective at reducing anxiety9espace.library.uq.edu.au/view/UQ:28410310www.ncbi.nlm.nih.gov/pubmed/2120858611www.ncbi.nlm.nih.gov/pubmed/1693080212www.sciencedirect.com/science/article/pii/S1756464611000351, causes relaxation while simultaneously increasing attention6espace.library.uq.edu.au/view/UQ:2841037koreamed.org/SearchBasic.php?RID=0124KJN/2003.36.9.918&DT=18www.sciencedirect.com/science/article/pii/S175646461100035112www.sciencedirect.com/science/article/pii/S1756464611000351, improves memory and decreases stress 22www.ncbi.nlm.nih.gov/pubmed/21739364 23www.ncbi.nlm.nih.gov/pubmed/23458739 24www.ncbi.nlm.nih.gov/pubmed/23395732 25www.ncbi.nlm.nih.gov/pubmed/21303262, and has neuroprotective qualities 13www.ncbi.nlm.nih.gov/pubmed/17182482 15www.ncbi.nlm.nih.gov/pubmed/21477654 16www.ncbi.nlm.nih.gov/pubmed/12499631.

As an analogue of glutamate, it’s main mechanism of action seems to come from modulating glutamate receptors. It binds to all three glutamate receptors (AMPA, NMDA, and kainite), acting as an antagonist of the former two and agonist of the latter 13www.ncbi.nlm.nih.gov/pubmed/1718248214www.ncbi.nlm.nih.gov/pubmed/1259686715www.ncbi.nlm.nih.gov/pubmed/2147765416www.ncbi.nlm.nih.gov/pubmed/12499631.

L-theanine has the unique quality of indirectly raising levels of dopamine, gaba, BDNF and NFG in the brain17www.ncbi.nlm.nih.gov/pubmed/956660519www.ncbi.nlm.nih.gov/pubmed/1718248220www.ncbi.nlm.nih.gov/pubmed/2186109421www.ncbi.nlm.nih.gov/pubmed/9566605, as well as mixed results with serotonin17www.ncbi.nlm.nih.gov/pubmed/956660518www.ncbi.nlm.nih.gov/pubmed/9614715. These effects account for some of its anxiolytic properties. The increase in BDNF and NGF levels and the neuroprotection account for some of it’s nootropic-like qualities.

For these reasons, l-theanine has known for some time to be quite synergistic (an effect greater than the sum of their separate effects) with caffeine and other stimulants. When taken together they are become more than merely the sum of the two parts. In other words, a combination of caffeine + l-theanine could be said to be 1+1=3 instead of 2 in terms of the effectiveness as a nootropic.

I have taken caffeine + l-theanine many times due to it’s relative cheapness, simplicity, and effectiveness. It’s a very reliable and well-rounded nootropic that can greatly enhance attention and can make zen-like flow states much more attainable.



Where to Purchase Caffeine + Theanine

nootropics depot

Caffeine + Theanine may be purchased at Nootropics Depot.

I recommend Nootropics Depot because they have been around for a long time and have maintained a solid reputation. They have excellent quality control metrics: they  do in-house testing as well as independent 3rd-party testing, and they have certificates of analysis available for all of their products.



Dosage Information

Recommended dosage is either a 1:1 ratio or a 2:1 ratio of theanine to caffeine. A standard dose would then be something like 200mg of caffeine and 200mg or 400mg of theanine. I would personally recommend a 2:1 ratio as theanine does not diminish the effects of caffeine in higher doses.




  1. content.iospress.com/articles/journal-of-alzheimers-disease/jad091384
  2. content.iospress.com/articles/journal-of-alzheimers-disease/jad111982
  3. www.ncbi.nlm.nih.gov/pubmed/20164566
  4. www.sciencedirect.com/science/article/pii/S030100820400125X
  5. link.springer.com/referenceworkentry/10.1007%2F978-0-387-79948-3_1340
  6. espace.library.uq.edu.au/view/UQ:284103
  7. koreamed.org/SearchBasic.php?RID=0124KJN/2003.36.9.918&DT=1
  8. www.sciencedirect.com/science/article/pii/S1756464611000351
  9. espace.library.uq.edu.au/view/UQ:284103
  10. www.ncbi.nlm.nih.gov/pubmed/21208586
  11. www.ncbi.nlm.nih.gov/pubmed/16930802
  12. www.sciencedirect.com/science/article/pii/S1756464611000351
  13. www.ncbi.nlm.nih.gov/pubmed/17182482
  14. www.ncbi.nlm.nih.gov/pubmed/12596867
  15. www.ncbi.nlm.nih.gov/pubmed/21477654
  16. www.ncbi.nlm.nih.gov/pubmed/12499631
  17. www.ncbi.nlm.nih.gov/pubmed/9566605
  18. www.ncbi.nlm.nih.gov/pubmed/9614715
  19. www.ncbi.nlm.nih.gov/pubmed/17182482
  20. www.ncbi.nlm.nih.gov/pubmed/21861094
  21. www.ncbi.nlm.nih.gov/pubmed/9566605
  22. www.ncbi.nlm.nih.gov/pubmed/21739364
  23. www.ncbi.nlm.nih.gov/pubmed/23458739
  24. www.ncbi.nlm.nih.gov/pubmed/23395732
  25. www.ncbi.nlm.nih.gov/pubmed/21303262

Jacob S

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