April 06, 2022 5 min read

L-theanine is an amino acid that may not be naturally found in the body, but researchers think it can have a big impact when taken as a supplement. It works similarly to glutamate, a naturally occurring amino acid that helps send nerve signals in the brain.

Some evidence suggests that theanine can help regulate neurochemicals like GABA, dopamine, and serotonin. So, it’s no surprise that research has found it to potentially boost focus, improve sleep quality, and even promote relaxation in those who suffer from anxiety or depression.

There are many physical and neurological reasons why you may want to supplement with this amino acid powerhouse, but there’s one important detail to work out– how much L-theanine should you take?

Here, we’ll dive into the details behind L-theanine dosage, like when’s the best time to take L-theanine and whether you should take it every day. Let’s go:

Table of Contents
How Much L-Theanine Should I Take?
What’s the Best Way to Take L-Theanine ?
When Should I Take L-Theanine?
Who Shouldn’t Take L-Theanine?
L-Theanine Dosage FAQs

Key Takeaways

  • Consumers often take 100-500mg of L-theanine daily, sometimes divided into multiple daily doses.
  • The exact dosage you need depends on your health condition, weight, age, and other biological factors. You may need to start with small doses and increase as needed.
  • There are no reported side effects for L-theanine, but some supplements contain caffeine and may cause side effects for some people who are sensitive to caffeine.

How Much L-Theanine Should You Take Daily?

Before we can dig into the question at hand–how much L-theanine should I take every day–we want to point out some important dosing factors. First, L-theanine is often used in the form of green tea or green tea extract, in which the actual L-theanine can’t be measured in accurate quantities. The dosage recommendations below apply to pure L-theanine in supplement form.

The actual amount of L-theanine you should take depends on unique factors like your weight, age, diet, and health effects you hope to achieve. You may need to start with smaller doses of L-theanine and increase your dosage overtime until you experience the full benefits.

Also keep in mind that L-theanine is sold as a supplement in the U.S., which means that the dosage size is not standardized. You should pay close attention to the dosage of any product you choose.

On average, people take between 100-500 mg of L-theanine daily, and the total dosage may be divided into three smaller doses taken throughout the day.

You may find that you need less L-theanine to experience the full benefits if you have a diet that’s high in theanine sources, like green and black tea and certain types of mushrooms.

You may also need less L-theanine to reap certain benefits if using other supplements to achieve the same cause. For instance, you may need less L-theanine to experience focus-enhancing effects if you take it with caffeine or other nootropics and supplements meant to enhance focus.

If you are taking a multi-functional blend that includes L-theanine, make sure you pay attention to the proper dosage threshold for other ingredients when adjusting your L-theanine dosage. These types of formulas are common, and it may be best in this case to just follow the recommended dosage on the label.

L-Theanine Dosage for Sleep

Some evidence suggests that L-theanine may help improve sleep in some cases, though the dosage varies for each person. One study found that participants supplementing with 450-900 mg of L-theanine reported better sleep quality than the placebo group.

L-Theanine for Focus

One study found that doses of 50 mg of caffeine or doses of 100 mg of L-theanine improved participant’s ability to perform Sustained Attention to Response Tasks (SART) over a two-hour session. The study found that the effects were not increased when these two substances were used in combination, suggesting that L-theanine may have cognitive boosting abilities even when not taken with caffeine.

A bowl filled with L-theanine capsules, a convenient dosing form for daily L-theanine doses.

What's the Best Way to Take L-Theanine?

L-theanine is primarily found in two main forms–capsules and powder. Each are used in similar quantities but there are a few advantages to either dosing method. Specifically, L-theanine powder can be a versatile dosing option that's used in creating unique blends that include other supplements, herbs, and wellness blends. Let's talk about these two main dosing methods:


L-Theanine powder is a convenient, popular option because it allows ultimate control over your dosage. It can be mixed into your favorite foods or drinks, and offers the ability to measure precise doses to meet your unique wellness needs. If you opt for a multifunctional herbal formula that contains other supplements, you may find it in powdered form. You can also use L-Theanine powder to add to empty capsules to create your own perfect doses.


Capsules are simply pre-measured, encapsulated doses that are great for daily dosing at any time of day. You won’t need to measure the dosage each time, and many people love this flavorless L-Theanine dosing option.

Looking for a tasty product that takes advantage of medicinal mushroom and nootropic ingredients like this? We recommend checking out Lucid Super Coffee.

When Should I Take L-Theanine?

Because L-Theanine is most commonly taken to boost productivity and balance mood, it may be best taken in the morning. Many people prefer to take their L-theanine with food, and it's often taken with small doses of caffeine that are thought to potentiate the effects. Some people also take L-theanine throughout the day, usually breaking their total dosage into two or more doses.

In most cases, you can take L-Theanine with your other supplements at whatever time works best for you. You just want to make sure that you take L-theanine daily around the same time each day for optimal effects.

Who Should Not Take L-Theanine?

There are little to no risks associated with taking L-theanine, assuming the supplements you choose are well-made and safe. Some L-theanine supplements contain caffeine, so people may have a sensitivity to caffeine and may need to pay attention to the caffeine dosage in certain formulas. There are a few rare cases where L-theanine supplementation could be dangerous, including:

  • When taking certain cancer medications, such as bortezomib, where L-theanine may decrease the drug’s efficacy.
  • When experiencing nausea, upset stomach, or irritability where caffeine may make it worse. In this case, an L-theanine supplement without caffeine may still be used.

In any case, always talk to your doctor before making changes to your wellness routine. Keep in mind that L-theanine is sold as a supplement in the U.S., and supplements are not as well-regulated as pharmaceuticals and over the counter medications. You should make sure that you only buy supplements from a trustworthy source to reduce the chance of L-Theanine side effects due to poor product quality.

L-Theanine Dosage FAQ's

What's the best L-Theanine dosage?

On average, most people take between 100 and 300 mg of L-theanine daily, sometimes broken into two or more daily doses.

How much L-theanine should you take for anxiety?

Some sources recommend taking 200 mg of L-theanine 2-3 times daily to manage anxiety. It’s important to note that more evidence is needed before L-theanine can be recommended as an anxiety treatment, but many anecdotal reports suggest that it may help.

Can I take L-theanine everyday?

Yes, L-theanine needs to be taken consistently to experience the full benefits.

Are there any side effects to L-Theanine?

There are no reported side effects for L-Theanine, but some L-theanine supplements also contain caffeine, which may have side effects like nausea, jitteriness, irritability, and gut irritation when taken in large quantities.


  1. “Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task” https://pubmed.ncbi.nlm.nih.gov/22326943/
  2. “L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial” https://pubmed.ncbi.nlm.nih.gov/30580081/
  3. “l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion” https://www.mdpi.com/2306-5710/2/2/13/htm
  4. “Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors” https://pubmed.ncbi.nlm.nih.gov/19190249/

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