Tea Health
What Is Theanine In Tea? – Tea Science

What Is Theanine In Tea? – Tea Science

I love science. I love understanding the reasoning behind why certain things work the way they do, how they function, & what they can do. This is why I love diving into the science of tea!

When you steep a cup of tea, there is so much going on chemically within that cup. Oils are being released to give it the flavor & smell, compounds are extracted from the leaves & transported into the water, bonds are breaking & becoming new beings, it is all so fascinating to me! One of those compounds that fascinates me so much is Theanine (aka L-Theanine).

This article is for those of you that love science & will answer the question “What is Theanine in tea?”. Let’s dive into the actual theanine compound, how it interacts with your body & mind, how tea effects it, & more!

The Theanine Compound

Theanine, or more commonly known as L-Theanine, is an amino acid found only in tea & some mushrooms. This amino acid is considered nonessential because it is not one of the 9 essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine). Essential amino acids means that our bodies cannot produce them naturally & therefore we must get them through our diet

Theanine was discovered in 1949 by Japanese scientists. It is an amino acid that may help promote relaxation without drowsiness. It has also been said to ease stress & tension & help individuals unwind. Other potential benefits include…

  • Better Focus!
  • Boosted Immune Function!
  • Improved Sleep Quality!
  • Lowered Blood Pressure!

How can this amino acid aid in so many ways? Let’s look into that a little further!

Theanine In Your Mind & Body

Theanine has some potentially cool benefits for you! How does this all work? Let’s break it down!

When it comes to theanine’s main function of promoting relaxation, there are a few mechanisms going on here that allow this to occur! Check out below the 3 main reasons we see this interaction.

  • GABA levels are boosted in the brain! GABA (aka gamma-aminobutyric acid) is a natural relaxing amino acid produced in our brains. It inhibits excitatory activity from the brain to the nervous system thus calming us down. When there are increased GABA levels, our body calms itself.
  • Increases Alpha waves in the brain! Alpha waves are neural oscillations that are associated with a state of “wakeful relaxation”. These waves naturally get released when you are meditating, being creative, or daydreaming. This is done via activity in the thalamic pacemaker cells in humans. L-Theanine however, has been shown to trigger the release of these waves.

Theanine may help boost sleep due to its relaxing effects. Many studies have shown it having success with longer, more restful nights of sleep. Check out the references below to learn more!

Tea & Theanine

The most abundant place to find theanine naturally is in tea. So how does theanine & tea interact besides the theanine providing these awesome health benefits? Theanine has actually been found to interact with tea’s other compounds in cool ways & possibly even affect the teas flavor!

Tea has caffeine. Now the quantity of caffeine varies with each cup, but a true cup of tea will have some bit of caffeine. Lucky for us, L-Theanine & caffeine were a match made in heaven! The caffeine boost that many of us know & love is actually enhanced due to the calming effects of theanine. This means that instead of crashing hard when the caffeine wears off, we gradually return to our decaffeinated state! This allows us to focus sharper & longer!

Theanine also has a profound effect on the taste of the tea you are consuming, & possibly even on your taste buds! Green tea tends to have an umami flavor that is earthy & vegetal. This may be attributed to theanine! Also, by consuming a lot of tea (& therefore a lot of theanine) your taste perception may change. People who drink lots of tea may find other bitter foods like dark chocolate & grapefruit more appealing! I can tell you personally that this one is true!

Teas With Most Theanine

Is theanine in all teas or just some select few? Well any “true tea”, meaning leaves from the Camellia sinensis plant (black, green, white, oolong, & pu’erh), all contain theanine! However, there are certain teas with a higher affinity for more theanine than others.

A rule of thumb is the less processed the tea-leaf, the more theanine you will find. Therefore, teas with the highest theanine (least processing/oxidation) are green & white teas! Shaded green teas like Gyokuro, ceremonial grade matcha, & Kukicha have probably the most.

To get the most “bang for your buck” when it comes to theanine, I would always recommend matcha. Good quality matcha has soooo many amazing benefits, so I will always recommend this. Check out the Fresh Steeps recommendations for matcha below!

Matcha Kari – Ceremonial Grade Matcha

Buddha Teas – Matcha

Let us know what your favorite is!

Theanine For Me

Now as always, make sure to understand the side effects of everything before you consume a new substance. Do some research of your own & consult your doctor first if you have any questions. Fresh Steeps is here to spark curiosity, thought, & hopefully expand on some knowledge!

Tea is so cool because it contains so much in a little cup. Theanine is just one of those awesome compounds! It can help aid in relaxation without making you drowsy, provide higher quality sleep, deeper focus, & overall make you feel healthier & stronger!

Hopefully we were able to answer the question, “What is theanine in tea?” & provide a little more knowledge! Let us know in the comments what you think!


  1. Theanine & Alpha Waves
  2. GABA & Theanine
  3. Theanine & Stress-Related Symptoms
  4. Theanine & Sleep
  5. Theanine & Immunity
  6. Theanine & Blood Pressure

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