L-Theanine and Tea: Which Teas Are Highest in L-Theanine?

L-Theanine, a naturally occurring amino acid found in tea, has been gaining attention for its potential health benefits.

In this article, we will delve into the world of L-Theanine, exploring its origins, the teas with high levels of this calming compound, and the effects it has on our body and mind.

Matcha powder
Matcha tea is especially high in L-Theanine

What Is L-Theanine?

L-Theanine, or gamma-glutamylethylamide, is an amino acid that was first discovered in 1949 by Japanese scientists. It is primarily found in the leaves of the Camellia sinensis plant, which is used to make green, black, and other types of tea. L-Theanine is also present in small amounts in certain types of mushrooms.

Its unique molecular structure enables it to easily cross the blood-brain barrier, which allows it to have a direct impact on the brain and nervous system.

Teas That Are High in L-Theanine

1. Matcha

Matcha is a powdered form of green tea that is especially high in L-Theanine. The shade-grown tea leaves used to make matcha have increased levels of L-Theanine due to the unique growing process. As a result, matcha is known to provide a calming effect while also boosting mental alertness.

2. Gyokuro

Gyokuro, another shade-grown Japanese green tea, is also known for its high L-Theanine content. The leaves are shaded for about three weeks before harvesting, which boosts the L-Theanine levels and gives the tea a unique taste and aroma. Gyokuro has a sweeter taste compared to other green teas, which can be attributed to its higher L-Theanine content.

3. Sencha

Sencha is the most common type of green tea in Japan and is also rich in L-Theanine. Although not shade-grown like matcha or gyokuro, sencha still contains significant amounts of L-Theanine that can help promote relaxation and focus.

4. Oolong Tea

Oolong tea is a partially fermented tea that falls between green and black tea in terms of oxidation. While its L-Theanine content may be lower than that of some green teas, oolong tea still offers a significant amount of this calming amino acid.

5. Black Tea

Black tea is fully fermented and contains lower levels of L-Theanine compared to green tea. However, it still provides a noticeable amount of L-Theanine, which can help promote relaxation.

The Health Benefits of L-Theanine

1. Stress Reduction and Relaxation

One of the most well-known benefits of L-Theanine is its ability to promote relaxation without causing drowsiness. Studies have shown that L-Theanine can help reduce stress and anxiety by increasing the production of calming neurotransmitters like GABA, serotonin, and dopamine in the brain.

2. Improved Sleep Quality

L-Theanine’s calming effects can also help improve sleep quality by promoting relaxation before bedtime. Research has shown that L-Theanine can help you fall asleep faster and enjoy deeper, more restful sleep.

3. Enhanced Cognitive Function

L-Theanine has been found to improve cognitive function by increasing the brain’s alpha wave activity. This increase in alpha wave activity is associated with enhanced creativity, focus, and mental clarity.

4. Boosted Immune System

Some studies have shown that L-Theanine may help support the immune system by increasing the activity of certain immune cells. This can help your body fight off infections and illnesses more effectively.

5. Cardiovascular Health

L-Theanine has been found to have potential benefits for cardiovascular health. Research suggests that it may help reduce blood pressure, lower cholesterol levels, and decrease the risk of heart disease.


L-Theanine is a unique amino acid found in tea, particularly green tea varieties like matcha, gyokuro, and sencha. Its calming and stress-reducing effects make it an appealing ingredient for those looking to enhance their overall well-being.

With a range of potential health benefits, including stress reduction, improved sleep quality, enhanced cognitive function, immune system support, and cardiovascular health, L-Theanine is a natural compound worth exploring.

Incorporating teas high in L-Theanine into your daily routine can provide a simple and enjoyable way to experience the calming effects of this amino acid. Whether you choose to start your day with a cup of matcha or unwind in the evening with a soothing oolong, you’ll be harnessing the power of L-Theanine to help support your overall health and well-being.

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