Caffeine + Theanine and its Synergistic Properties


Last Updated on


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 right1, 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 them3

Adenosine is a neurotransmitter which builds up over the course of the day and is used to signal to our body that we are tired4 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 Law5, 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, causes relaxation while simultaneously increasing, improves memory and decreases stress, and has neuroprotective qualities

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

L-theanine has the unique quality of indirectly raising levels of dopamine, gaba, BDNF and NFG in the, as well as mixed results with 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


Caffeine + L-Theanine Capsules

Nootropics Depot is recognized for having some of the best quality-control measure in the industry and utilize both in-house and 3rd-party testing facilities. They also provide certificates of authenticity for all of their products.



Caffeine + Theanine Dosage Information

Recommended dosage is either a 1:1 ratio or a 2:1 ratio of theanine to caffeine. Therefore a standard dose would be something like 100mg of caffeine and 100/200mg of theanine.