The Benefits Of L-Theanine

L-theanine is a natural compound that is associated with a body of research. The compound is classified as an amino acid. This means it plays a role in the production of proteins in the body. Some studies also suggest that L-theanine holds additional benefits, particularly for the mind.

We take a closer look at L-theanine benefits, what the best sources are, and if there are any side-effects to be taken into consideration. 



What Is L-Theanine?

L-theanine is a type of amino acid. This is an amino acid that the body is unable to produce on its own. With this in mind, the only way to obtain L-theanine is to use supplements or use a natural source of the amino acid. 

In many cases, L-theanine is used to promote relaxation. It is often used by people who find that other products that may relax them cause drowsiness. The supplement is sometimes used before bed, which may help a person experience elevated sleep quality too. 


One study shows that L-theanine is found in a variety of teas [1]:


  • White tea
  • Oolong tea
  • Black tea
  • Green tea



L-Theanine Health Benefits

There are several L-theanine amino acid benefits that you can enjoy—whether drinking a cup of tea or taking a supplement. A product like Hydrant ENERGY is also something to consider. Our mixes contain 200mg L-theanine, along with 100mg caffeine—specifically designed to help with energy and focus. When caffeine and L-theanine are together, they work like a great superhero pairing to promote sustained energy. 

Hydrant caffeine line

We take a closer look at a few of the most important benefits that have been associated with L-theanine.


Reduces Anxiety

The calming properties of L-theanine remain one of the most popular benefits associated with amino acids. There are multiple studies that have been conducted on the calming effects of L-theanine. This particular effect may provide a reduction in anxiety and act as a stress-relieving agent. 

One journal entry described the results of five studies [2]. There were five randomized-controlled clinical trials included in the results. Among the studies, there were 104 people who participated. Researchers report that the supplement was able to provide a reduction in anxiety scores. Stress symptoms were also lowered among the individuals who took the supplement. 

In another clinical trial, L-theanine was tested on subjects with schizophrenia [3]. Researchers found that there was an improvement in anxiety symptoms among these patients. Like all studies, more research is needed for conclusive claims with this product, but it’s promising to review the materials. 


Immune Support

The use of L-theanine may also be useful as a way of supporting the immune system. The body’s immune system acts as a defensive mechanism. A strong immune system can help the body fight against viruses, bacteria, and other pathogens. 

immune system mask on

According to some studies, multiple areas of the immune system may be improved with the use of L-theanine. 

A study was done to see how L-theanine affects the part of the immune system found in the gut [4]. The subjects who took the supplement were able to experience an improvement in inflammation within the gastrointestinal system. Low-grade inflammation has been associated with a number of chronic diseases. 


May Improve Blood Pressure

High blood pressure is dangerous and can lead to serious adverse effects—including an increased risk of heart disease and heart attacks. It is well-known that stress can lead to an increase in blood pressure. 

The fact that L-theanine can reduce stress may also be helpful in some cases of high blood pressure. In one study, there was an improvement in blood pressure levels among people with stress – particularly after the subjects were provided with a supplement that contains L-theanine [5]. 


May Help With Sinusitis

Sinusitis is a common problem that causes inflammation in the nasal cavity. There may be postnasal drainage, congestion, and even pain in the area. Some people also experience a reduction in their sense of taste or smell. 

The symptoms can be quite unpleasant. According to some research papers, L-theanine could be a useful way to possibly reduce these symptoms. One medical book notes that cilia movement in the nasal cavity may be improved with the use of the L-theanine [6]. 


Could Improve Sleep

Sleep is a critical part of life. When a person fails to sleep enough, they may experience a wide range of both short-term and long-term effects. A large number of individuals suffer from sleep deprivation, which could have a serious impact on their daily life. 

There are studies that show L-theanine may be a useful way of improving sleep. In one study, a variety of doses were tested, up to 400mg [7]. Even at a dose of just 200mg, L-theanine showed promising results in reducing the heart rate while also relaxing the mind. 

L-theanine may be useful in improving sleep among both kids and adults. In one study, boys between the age of eight and 12 were considered [8]. A 200mg L-theanine dose was provided at night. There was a significant improvement in sleep among these boys. 



Are There Side-Effects?

Currently, no evidence is available that suggests there are dangers behind the use of L-theanine. It should be noted that there is also little research on doses considered safe when taking L-theanine. With this in mind, it is generally advised to avoid taking excessive doses of the amino acid. 

cup of green tea

In its natural form, one would usually drink green tea to obtain L-theanine (and is where the caffeine in Hydrant ENERGY comes from). Green tea is caffeinated. This means people who are sensitive to caffeine may experience adverse effects. 




The amino acid L-theanine is naturally found in tea leaves, as well as a few other sources. Using a supplement with L-theanine may yield a relaxing effect on the human body. A major benefit is that the relaxation is produced without causing side-effects like drowsiness. L-theanine may help with reducing blood pressure, improve sleep, and even be a helpful way of reducing anxiety. When combined with caffeine, it can help with a focused stream of energy.