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The Famous Relaxation Effect of L-Theanine

The Famous Relaxation Effect of L-Theanine

Have you ever drank green tea? For some, this is a real treat that helps them warm up during cold days. Others are having difficulties with handling the specific taste, especially without sugars or other ingredients added to the tea.

However, no one seems to question that green tea comes with various benefits.

These benefits include accelerating fat burning and weight loss, improving brain function, and having antioxidant properties. L-theanine is one of the green tea components that can have positive effects on human health and wellness.

Among other benefits, it should have a relaxation effect that promotes calmness and provides anxiety relief.

Is there any truth in that claim? Here is what science has to say about the connection between L-theanine, anxiety, and relaxation!

What Is L-Theanine?

L-theanine is an amino acid that has only a couple of natural sources. Those include mushrooms and green tea. Apart from those sources, you can also consume it in the form of supplements.

These solutions often have purified variation of this amino acid. L-theanine belongs to non-protein amino acids, which means it can go through the blood-brain barrier. That allows it to have numerous benefits, such as calming effects, modulation of dopamine and serotonin, etc.

It doesn’t seem that L-theanine has any side effects.

However, if you get it from green tea, that beverage can cause stomach irritability and nausea. That side effect, however, is probably due to the caffeine, which is also found in green tea.

Can L-Theanine Be Effective in Promoting Relaxation and Positive Mood?

Science has been trying to answer that question for a long time.

According to multiple studies, the primary benefit of L-theanine is that it boosts the effectiveness of antidepressant and antipsychotic therapies.

Research Study 1 (L-Theanine for Anxiety)


A study published in Physicians Postgraduate Press in 2010 focused on patients with schizoaffective disorders and schizophrenia.

A total of 60 participants agreed to participate in an eight-week study. The participants were divided into a control group and a category that received 400 milligrams daily of L-theanine.

Although a third of patients dropped out, the results received were encouraging. The researchers used the HARS scale to assess the severity of anxiety symptoms.

Both the anxiety scores and general psychopathology ratings were improved after treatment with L-theanine.

Additionally, the study confirmed the patients showed the medication was well-tolerated and safe.

Research Study 2 (L-Theanine for Anxiety)


Another study was published in the Journal of Psychiatric Research in 2019. Its focus was on the participation of L-theanine in treating a generalized anxiety disorder.

The study involved 46 patients diagnosed with GAD. Since it was placebo-controlled research, some participants received a placebo, while others got 450-900 milligrams of L-theanine daily. It is worth noting that the patients also received regular therapy containing antidepressants.

The results indicated that the participants reported they slept better when consuming L-theanine.

That means this amino acid could contribute to relaxation, and help to promote an optimal sleep pattern.

Research Study 3 (L-Theanine for Anxiety)


Here is another interesting study concerning the correlation of L-theanine and anxiety relief. According to this research, L-theanine doesn’t have an anxiolytic effect on its own.

However, the results clearly showed that this amino acid boosts the effect of midazolam or works well when combined with it.

It is another scientific evidence that using L-theanine as supplemental therapy could assist in providing anxiety relief.

Research Study 4 (L-Theanine for Anxiety)


In 2018, the researchers from Japan published the results of their rat-focused study in Psychopharmacology. Although it was another animal study, the results were once again encouraging.

After conducting multiple tests, the researchers concluded that L-theanine has anxiolytic properties and boosts the activity of the hippocampus in rats.

Research Study 5 (L-Theanine for Anxiety)


Cats were the focus of another study whose results were published in 2018. The researchers focused on potential emotional signs related to stress, and their decrease after consuming L-theanine tablets.

The study revealed that it took two weeks to show the first improvements in reducing stress manifestations.

A further improvement was noticed after four weeks of a regular intake of this amino acid. The only downside of this trial is that it didn’t include a placebo group.

Research Study 6 (L-Theanine for Immediate Short-Term Relaxation)


An important study was revealed in the Trends in Food Science & Technology over two decades ago.

The article explains how L-theanine and green tea delivers the relaxation effect for the user after consuming it. The scientists have given this amino acid to human volunteers and noticed an interesting effect.

It took approximately 40 minutes to show relaxation signs.

The participants reported that they felt more relaxed but not drowsy. That is important because L-theanine doesn’t make you sluggish while providing a relaxation effect.

Research Study 7 (L-Theanine for Immediate Short-Term Relaxation)


Another study confirmed the same effect of L-theanine. It included administering 50 milligrams of this amino acid to young and healthy volunteers. A total of 35 participants were divided into two groups – 16 that received the actual L-theanine, and the rest who received a placebo.

The researchers used EEG recording while participants held their eyes closed and rested. The idea was to measure the alpha activity in the brain at intervals from 45 to 105 minutes from consuming L-theanine.

The results showed that this amino acid is capable of relaxing the mind while ensuring optimal alertness and attention span.


If you are not a fan of drinking green tea, you can find L-theanine in various supplements.

Those dealing with anxiety and looking to relax should consider supplements designed for that purpose.



  1. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/l-theanine
  2. https://www.researchgate.net/profile/Michael_Ritsner2/publication/49731066_L-Theanine_Relieves_Positive_Activation_and_Anxiety_Symptoms_in_Patients_With_Schizophrenia_and_Schizoaffective_Disorder_An_8-Week_Randomized_Double-Blind_Placebo-Controlled_2-Center_Study/links/0046352bb0e3d6d672000000.pdf
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  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6178259/
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  8. http://apjcn.nhri.org.tw/server/APJCN/17%20Suppl%201/167.pdf


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