Nootropic Review: Caffeine + L-Theanine

Nootropic Review: Caffeine + L-Theanine

A safe, simple stack.

So you’ve already been introduced to the concept of Nootropics and are looking for a low-barrier point of entry to start experimenting. This review is the first of many in a series that will systematically break down and explain a number of the most popular Nootropics. I’ll cover their use cases, ideal stack partners, and potential side-effects, as well as any personal experience I may have with a given substance.

To start off, I’ll be reviewing what may be the most popular Nootropic stack there is: Caffeine and L-Theanine.

Caffeine - A Quick Overview

Caffeine is the most popular single Nootropic on the planet. Its application as a stimulant to food and drink in modern society has become practically universal, and it can be found in everything ranging from snacks to energy drinks. Here’s a research-backed breakdown of its effects and applications:

Nootropic effect: Mental stimulant.

Positive effects (Short-term):

Negative effects (Short-term):

Should I cycle caffeine?


Consuming caffeine on a regular basis builds a tolerance towards a number of its effects. Most notably, the ‘caffeine rush’ and improvements to alertness and endurance are all greatly diminished in strength (or outright absent) after just a few weeks of supplementation, and require successively larger doses in order to maintain their occurrence.

Fortunately, the most commonly sought-after benefit of caffeine—its wakefulness promoting properties—do not seem to have any tolerance-related fall-off. While caffeine may subjectively not ‘feel’ as good as it did the first time if it’s consumed habitually, if one’s primary goal is to stay awake, it will indefinitely serve that purpose at around the same level of effectiveness.

Potential Risks:

To address these potentially worrisome risks; while they are important to keep in mind for this substance, as with the associated risks of any other, there’s relatively little to worry about when it comes to caffeine. It’s been employed as a tool for human productivity for millennia, and so long as responsible use of the substance is maintained, you’ll be fine.

L-Theanine - A Quick Overview

L-Theanine is a non-essential amino acid that is primarily used for its ability to both reduce anxiety and promote relaxed states of mind, notably without any associated sedative effects. If you’re familiar with the calming effect of Green Tea, this is the chemical responsible for it.

The effects of L-Theanine are due to its inhibitive effect on circulative cortisol in the brain. This mechanism has a number of consequent benefits, such as higher sustained periods of attention in persons suffering from chronic anxiety, and improved quality of sleep for those suffering from hyperactive disorders.

Nootropic effect: Stress inhibition without sedation.

Positive effects (Short-term):

  • Reduced stress response

Negative effects :

  • L-Theanine has no notable negative effects, short or long-term. It is neither habit nor addiction-forming on a physiological level, and due to the body’s ability to metabolize excess amino acids through deamination, it thus is practically impossible to abuse or overdose. The body will simply excrete what it does not need through urination.

Should I cycle L-theanine?


There’s no need, due to a lack of tolerance-forming effect.

The Stack

I’m sure most people reading this will by now have guessed the interaction taking place in this beginner-friendly stack.

L-Theanine’s stress-mitigating effects pair incredibly well with Caffeine, allowing you to negate its trademark jitters without affecting any of the stimulatory benefits. The result, as it’s often accurately described, is a ‘clean rush’.

The combination can be found in pill form containing factory-measured splits between each compound. Typically, this will consist of either 100mg Caffeine with 200mg L-Theanine, or otherwise the ratios will be reversed (Nootropics Depot). As with all Nootropics, different people will experience different results with each balance, and so experimentation may be necessary in deciding which is right for you.

That said, I find a good basis for making your decision on which to try first is your prior history with caffeine. (See ‘Personal Anecdotes’, down below)

Regarding cost—which is a benefit I don’t see brought up often enough—it can be bought for as little as 60 capsules for $14 (see the ‘Recommended Suppliers’ section), with each one containing as much caffeine as the average cup of coffee. This is an incredibly cost-effective and convenient way to get a caffeine fix without needing to go through the trouble of buying or brewing a whole cup. In fact, I tend to keep a bottle with me at all times just in case I need a boost that costs me all of 10 seconds and 23 cents. That’s huge for someone like me who hates the bitter taste of coffee.

Personal Anecdotes

Personally speaking, I’ve gone years on end without touching coffee as an adult (due to aforementioned dislike of the taste, benefits be damned). Prior to ordering my first batch of pills, I hadn’t had a cup of the stuff months, and the last time I did it was because a coworker just didn’t feel like drinking what they’d ordered. As would be expected, my tolerance towards caffeine is incredibly low, and so I opted for the 1:2 C+T option from Nootropics Depot.

My guesstimation paid off, and my experience with this stack has been the perfect balance. A single pill is enough to last me just around 5 hours before wearing off entirely, allowing ample time to put its boost to use without worrying about my sleep quality being affected.

If you’re like me and only supplement caffeine once a week or less, this mix should be ideal for you.

By extension, if you’re a habitual user, you might have better results from a 2:1 split.

Recommended Suppliers

Here’s a list of suppliers that I’ve found to be reliable both in quality and speed of delivery:

Nootropics Depot – (Also available on Amazon)


100mg:200mg Caffeine/L-Theanine Capsules – $14 for 60 / $28 for 180

200mg:100mg Caffeine/L-Theanine Capsules – $15 for 60 / $30 for 180

My go-to supplier for all things Nootropic. They’ll often have the lowest prices and the highest quality for any given compound. I also award bonus points due to their frequently available discount codes for purchases over a certain amount (or for first-time buyers), and free shipping for purchases over $50. If you’re choosing them, I recommend buying direct from their website.

LiftMode – (15% Discount Code) (Also available on Amazon)


100mg:200mg Caffeine/L-Theanine Capsules – $14 for 60

Another direct supplier with a good reputation in the online Nootropic community. In my experience they’ve been just as reliable as ND, and my choice to buy from the former most of the time simply boils down to having tried them first. If price is a deciding factor for you, using my link to their page nets you a 15% discount on your first purchase, so weigh that into your decision for which supplier to go with.

Amazon’s Top Pick – (Supplied by Sports Research)


100mg:200mg Caffeine/L-Theanine Capsules – $21 for 60

I reviewed Amazon’s most popular offerings for this stack and recommend this one based on user feedback. The stack provided by Sports Research is by far the most popular and well-reviewed on Amazon at the moment. At 60 caps for $21, the price per dose works out to 35 cents. It’s not as low as buying direct from a supplier, but if you trust Amazon as a middle-man, it’s the best option available.

NOTE: Amazon can be a mixed bag when it comes to vetting retailers.

If you want to check out other Nootropic suppliers on the platform, the following have generally clean track records when it comes to supplying goods as-advertised (I don’t personally vouch for any of their offerings—only their user satisfaction specifically when it comes to Nootropic products): NatureMade, Kirkland Signature, TruNature, Now Foods, Doctor’s Best, NutriGold.


That brings us to the end of my review for the Caffeine + L-Theanine stack. As stated, if you’re curious about the world of Nootropics and are looking for a simple, safe entry point, this is a great place to start.

Please bear in mind my warnings about the addictive properties of Caffeine.

I get my best results from this stack by only using it once or twice a week at most, and only when I really, really need the edge it gives. While taking it on a daily basis is just as safe as drinking tea or coffee, it’s very easy to develop a mental and physiological dependence on caffeine if caution is not exercised, and furthermore, you flat out won’t enjoy it as much if you overdo it.

There are other Nootropics that can be supplemented on a daily basis for a period of weeks, months, or even indefinitely without any negative effects or tolerance build-up. If and when I cover these, I’ll specify these properties in their respective articles.

Further Reading

If you’re interested in learning more, check out the following links:

Modafinil/Adrafinil Review – Odds are that if you’re eyeing caffeine as a supplement for productivity, Modafinil is right up your alley. It has similar anti-fatigue properties to Caffeine, but with the significant upsides of having no significant tolerance build-up, and no subsequent crash. While it’s nowhere near as potent as a stimulant, the overlap in applications between the two is large enough that your should consider learning more about it.

Magnesium Glycinate Review – L-Theanine’s relaxant effects may have caught your interest beyond its application in this specific stack. As a Nootropic, however, it tends to be rather short-lived in its effect. If you’re suffering from chronic stress, it’s possible that Magnesium supplementation might be more effective as a long-term solution. This article will explain why you should consider it.

Articles – I talk about more than just this one topic. You can find all my analytical writing here.

Nootropic Articles – If you specifically want to see what else I’ve written on Nootropics, here’s a link to its tag on my site.