Also Known As Theanine, L-5-N-Ethyl-Glutamine
  • Natural, Adaptogen
Good for
  • Anxiety
  • Focus
  • Learning
  • Mood
Stacks Well With
  • Caffeine
  • 5-HTP
  • Green Tea Extract
Dosage 10-200 mg
Half-life 2-5 hours

L-theanine is a natural amino acid that can be found in green tea and a particular edible mushroom, and it is excellent for reducing stress and anxiety, promoting relaxation, and improving focus, mood and sleep.


L-theanine is extracted from the leaves of the evergreen shrub or small tree from the Theaceae family called Camellia sinensis. The leaves and leaf buds of this plant from China are used to make green and white teas, as well as some black and oolong teas.

L-theanine is also extracted from the edible mushroom called Boletus badius, which can be found in the United States, usually in late summer and autumn.

Since green tea is known to promote relaxation and provide a calming effect, it certainly does not come as a surprise that L-theanine does exactly the same. What’s more, this amino acid was proven to improve memory, focus, and the ability to learn, which is why it is widely considered a nootropic.

L-theanine has a chemical structure that is very similar to the proteinogenic amino acids L-glutamate and L-glutamine, which are naturally found in our bodies. These amino acids play a great role in the neurotransmission of impulses in the brain so L-theanine, being similar to them, provides the brain with the same benefits and supports its health.

L-Theanine Benefits and Effects

L-theanine is one of the best natural nootropics you can get your hands on, because it boosts your cognitive functions and relaxes you, without inducing sedation. It enhances your memory, focus and alertness, improves your ability to learn, and reduces your stress, while at the same time providing you with a nice calming effect, without actually making you doze off.

This is exactly why L-theanine is gaining more and more popularity as a dietary supplement, as it can really provide you with incredible benefits and, more importantly, it is completely natural. Here is the list of all L-theanine benefits that you can experience by using this amazing nootropic supplement.

Providing Relaxation and Reducing Stress

One of the most widely known L-theanine benefits is its ability to provide you with the feelings of relaxation and peacefulness. It relaxes you and improves your mood, thus improving your general sense of well-being and enhancing your state of mind.

Since it relaxes you, L-theanine actually helps you reduce stress and the symptoms of anxiety and depression. As a result, it fills you with optimism and motivation.

L-theanine is one of the best natural nootropics you can get your hands on, because it boosts your cognitive functions and relaxes you, without inducing sedation.

Improving Focus and Alertness

L-theanine can also greatly boost your concentration and energy, helping you stay focused and improve your productivity at work or in school. Although it provides you with feelings of calm, pleasure and peacefulness, helping you relax, it makes you alert at the same time and gives you the motivation you need in order to perform any kind of task at hand.

These L-theanine effects make this supplement seem like a kind of a stimulant, but without the typical side effects that usually come with stimulants, such as jitters or nervousness and restlessness. This is precisely what makes it so great and why it is becoming more and more popular all around the world.

Improving Sleep

L-theanine improves sleep, but not in the way that you may think. It improves the quality of your sleep without actually inducing it. Since it improves your alertness, it wouldn’t make any sense for it to make you sleepy at the same time, would it?

Stress is one of the main culprits for poor quality sleep and you cannot really get a good night’s rest when you are under a lot of stress. Therefore, since L-theanine helps you reduce stress and anxiety, it effectively improves your sleeping patterns, thus making it much easier for you to fall asleep at night.

Boosting the Immune System

Of all the L-theanine benefits, the one that not so many people are probably aware of is the ability of this supplement to boost your immune system. If taken regularly and in proper doses, L-theanine can help you strengthen your immune system and improve your body’s resistance to cold and fever.

Reducing Blood Pressure

Other lesser known facts about L-theanine is that is can reduce blood pressure and improve overall cardiovascular health. This really goes without saying, since it reduces your stress levels and helps you relax, which ultimately leads to lower blood pressure.

Supporting Brain Health

L-theanine also supports brain health by preventing oxidative stress and protecting neurons from damage by free radicals. It is also known to improve cognitive functions and promote nerve growth.

This is why this supplement is considered to have very positive effects on the brain concerning cognitive functions in patients with Alzheimer’s disease, dementia and other similar neurodegenerative disorders. Due to its nerve growth abilities, it is also believed that it could help in treating Parkinson’s disease, but there is still very little research that can prove this.

How L-Theanine Works

How does L-theanine work and help you experience all the aforementioned benefits? Although numerous neuroscientists are still exploring all the ways L-theanine actually functions in the body, there are some things that have been proven and that show us exactly how this nootropic supplement regulates stress and produces relaxation.

The oral ingestion of L-theanine enables the supplement to quickly reach the brain and enter the central nervous system, since it is absorbed into the bloodstream very quickly. When it reaches the brain, it effectively regulates, that is, increases alpha brain waves. That is why it makes you alert and improves your focus and clarity.

When L-theanine reaches the tissue in the brain, it effectively taps into the neurotransmitters and receptors that are responsible for regulating stress, attention, pleasure and arousal. By reaching the GABA (gamma-Aminobutyric acid) neurotransmitter, which is the main inhibitory neurotransmitter in the central nervous system, L-theanine prevents over-stimulation of the brain cells and protects neurons from damage by preventing oxidative stress.

As a result, the brain is calmed down, so you feel much more relaxed and at peace. Consequently, any feeling of stress and restlessness is successfully eliminated, making room for tranquillity and relaxation.

L-theanine is also known to increase the level of serotonin, which greatly helps with regulating your circadian rhythm (sleep and wake cycle). This is why it can help you improve the quality of your sleep. It also increases the levels of dopamine and norepinephrine in the brain, which is why it improves your mood and helps you feel much better.

L-theanine has also been proven to improve cardiovascular health and reduce the risk of cardiovascular diseases by stimulating the production of nitric oxide. Nitric oxide is a molecule produced by endothelial cells that line the arteries, and it serves as a powerful vasodilator that relaxes and opens the blood vessels.

Since this reduces blood pressure and improves overall circulation, it lowers the heart rate and effectively improves cardiovascular health.

L-TheanineL-Theanine Dosage

First and foremost, you should know that L-theanine works best when it is combined with caffeine, so you should definitely use them together. However, if you are particularly anxious, it might be best that you steer clear of caffeine, as it may increase the symptoms of anxiety and not actually help you experience the benefits of L-theanine.

So, what is the right L-theanine dosage that you should be taking? The recommended L-theanine dosage is between 50 and 200 mg per day. If you have never taken L-theanine before, the smartest choice may be to start with 50 mg per day and then work your way up (without exceeding the maximum amount of 200 mg) until you find the perfect balance that will work for you.

You should take L-theanine once or twice a day, depending on your individual needs. If you decide to take it twice a day, make sure that you divide your daily dosage into two equal parts.

It is definitely good to know that you need to take your L-theanine dosage in the morning if you want it to help you relax and reduce stress. On the other hand, if you want to improve your sleeping patterns, take L-theanine one hour before you go to sleep, but make sure that you take a slightly higher dosage than the one you take in the morning or earlier in the day.

L-Theanine Stacking

Although L-theanine is excellent on its own, you will certainly get the most out of it if you stack it with other supplements. Here are the best and most effective L-theanine stacking examples that you should definitely give a try.

L-Theanine and Caffeine

An L-theanine and caffeine stack creates a very powerful synergy that can help you significantly enhance your cognitive functions, as well as improve your focus and alertness. What’s very interesting about this particular stack is that L-theanine actually eliminates some of the effects of caffeine.

Namely, it completely counteracts the jitters that caffeine may make you feel, helping you become much more relaxed and peaceful. Therefore, an L-theanine and caffeine stack improves your focus and mood, and reduces stress and anxiety, at the same time boosting your energy, memory and motivation.

The consumption of L-theanine is completely safe, and it has been granted a GRAS (Generally Recognized as Safe) status by the FDA (Food and Drug Administration)

If you decide to take L-theanine with caffeine, you should make sure that you always maintain the recommended ratio of 2:1. Therefore, if you take 200 mg of L-theanine, make sure that you do not take more than 100 mg of caffeine. Also, if you don’t happen to drink coffee, keep in mind that you should start with a lower dosage of caffeine, preferably 50 mg per day, when you would take 100 mg of L-theanine per day.

L-Theanine and Green Tea Extract

Since L-theanine is actually derived from the leaves of the plant that are used to make green tea, it really goes without saying that this particular stack can bring you quite a lot of benefits. By taking L-theanine and green tea extract together, you will be provided both with numerous health benefits of the extract and with all the relaxing benefits of this nootropic supplement.

L-Theanine and 5-HTP

5-HTP (5-Hydroxytryptophan) is a natural amino acid that is a precursor of the neurotransmitter serotonin and, as such, it provides excellent mood-lifting benefits. Therefore, combining 5-HTP with L-theanine can help you feel relaxed and calm, while having your mood greatly improved at the same time.

L-Theanine Side Effects

L-theanine is one of the very rare supplements that have no serious or harmful side effects if taken responsibly. This is not due to lack of research, because plenty of studies have been conducted and each and every one of them proved that L-theanine is perfectly safe.

Just think about it: people have been drinking green tea for thousands of years and all that was ever said and proven about this tea is that it is very beneficial to our health. Given the fact that L-theanine is extracted from green tea leaves, it goes without saying that it is perfectly healthy.

The only potential L-theanine side effects include a mild headache and dizziness, which may occur in very rare instances and only when taken with caffeine. However, these potential side effects can occur if you exceed the recommended L-theanine dosage, which is again not very likely to happen.

The third potential side effect is a mild gastrointestinal distress, which can happen only if you take L-theanine in extremely high doses.

Therefore, as you can see, the consumption of L-theanine is completely safe, and it has been granted a GRAS (Generally Recognized as Safe) status by the FDA (Food and Drug Administration).

However, keep in mind that you should not take L-theanine if you happen to have low blood pressure or you are taking medications to reduce it, because that combination may lower your blood pressure to a dangerous level.

Also, if you are taking any other kind of supplements, make sure that you consult with your doctor before implementing another supplement into your daily routine, so that you can be absolutely sure that you will not experience any potential side effects. It’s always better to be safe than sorry, and it is your health that is at stake, so don’t underestimate the professional opinion of an experienced doctor.

Where to Buy L-Theanine

In order to make sure that you buy good and safe products, you need to know where to buy nootropics. You can buy them in numerous physical stores, but online is where you will find them in their purest forms, since they cannot actually be sold that way as dietary supplements.

You can find a wide variety of L-theanine supplements online, but the best and safest place to buy them is definitely Amazon. We have done some research to help you narrow down your list, and the following ones are the best and most effective L-theanine supplements you should try.

The L-theanine supplement made by Sports Research has been clinically proven to promote relaxation and increase alertness by increasing alpha brain waves, without promoting drowsiness and inducing sleep. It is formulated with organic coconut oil, it is completely gluten-free, and it is encapsulated in a liquid softgel in order to improve the L-theanine absorption.

Like all other Sports Research products, this L-theanine supplement comes with a 90-day money-back guarantee.

Buy from Sports Research

This L-theanine supplement by NOW Foods promotes relaxation and supports healthy cardiovascular function. It also contains Inositol, which is a member of the Vitamin B family that is vital for the health of the brain and central nervous system.

It is great for stress management and one bottle contains 120 vegetarian capsules that are best taken with meals.

Buy from NOW Foods


As you are certainly aware by now, L-theanine is one of the best natural nootropics that can help you elevate your mood, improve your focus and alertness, and enhance your cognitive functions, while at the same time reducing your stress and making you feel completely relaxed and optimistic.

This is precisely why it is one of the most popular natural supplements and why you should absolutely give it a try. The sooner you implement it into your daily routine, the sooner you will experience all the amazing benefits that is has to offer, so take a step forward and start your journey to enhanced mental performance today.


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