L-Theanine: The Secret Ingredient In Green Tea

L-Theanine: The Secret Ingredient In Green Tea

July 14, 2019



What is L-Theanine?

L-Theanine (r-glutamylethylamide) is a non-dietary amino acid found in tea. Green tea contains exceptionally high levels of L-theanine. L-Theanine is an analogue of the amino acids glutamate and glutamine. It is broken-down in the intestine and liver into l-glutamate and ethylamine.

Quick Fact: L-Theanine easily crosses the blood-brain barrier, and is therefore known to be beneficial to the brain and for mental health.

L-Theanine is one of the very few nootropics known to modulate brain waves. It affects the alpha brain waves which are associated with relaxation. This is one of the reasons why L-theanine is used to help in relieving stress, and improve cognition

How It Works

L- Theanine helps increase alpha brain waves which are associated with mental relaxation and concentration. Further, research shows that L-theanine increases neurotransmitters dopamine, serotonin, and GABA in the brain. Moreover it reduces the excitatory neurotransmitter glutamate which is associated with stress, tension and agitation.In addition, L-theanine is also known to reduce heart rate and the levels of antibody s-IgA that is again associated with acute stress.


What are the best sources of L-theanine?

L-Theanine is a naturally occurring amino acid found in plants like tea or one species of mushroom. L-Theanine is available in green, black and white teas. Green tea contains the most L-Theanine.

Which is the best way to use L-theanine?

Studies have shown that the combined effects of L-Theanine and caffeine on cognitive performance and mood.

Quick Fact: The combination of L-theanine and caffeine has also been shown to improve speed, accuracy, and reduced tendency get distracted during tasks involving memory skills.

In addition L-theanine prevents the jittery feelings that are often associated with caffeine consumption.


What are the benefits of l-theanine?

Some common benefits of l-theanine are given below:

  1. Produces a calming effect on the body.
  2. Reduces risk of stroke
  3. Improves memory
  4. Reduces stress

Quick Fact: Research has shown that if L-theanine is present in the body at the time of a stroke attack, brain damage may be significantly reduced.

Further, L-theanine has also shown to increase brain theta waves which are associated with cognitive alertness and creativity. Corticosteroids are hormones which are secreted after stress. In an animal study, corticosteroid levels were lower in rats which were given L-theanine. Some studies have also reported that L-theanine curbs anxiety and panic attacks.


Recommended dosage of L-Theanine is 200 – 400 mg once or twice per day.

Quick Fact: Green tea that’s steeped correctly may contain 1-2% L-theanine per cup.

Individuals who are taking L-theanine supplements for the first time are usually advised to start with a lower dose like 100 mg per day, and progressively increase the dosage. We suggest starting with a dose of 100 – 250 mg of L-Theanine daily for nootropic use. Using either a quality supplement, or high quality green tea.

AIWO Recommendation: L-Theanine 250 mg per day

Safety and Side Effects

L-Theanine is generally considered non-toxic and very safe to consume.

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