L-Theanine And Anxiety


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Written by Phillippa Quigley

Holistic health and wellness coach Phillippa Quigley takes a look at the partnership between L-theanine and anxiety, and how they react together to massage a calmer, happier you.

Most adults at some point in their life will have suffered from a bout of anxiety. Whether it is the gut-wrenching feeling before a presentation or the daily worry of how you are going to manage to get all your things done. It could be that perhaps it is something you are suffering from all the time and has become overwhelming and exhausting.

Anxiety for some can be a debilitating chronic disease. Whilst there are many medicated routes you can take to treat anxiety, there are other natural solutions which can ease your symptoms.

L-theanine is one of them. It is a naturally formed compound that acts similar to anti-anxiety medication.

In this article we will discuss what L-theanine is and how it helps reduce anxiety. We will also discuss where you can source it from as well as any side effects it may have.

What is L-theanine?

Discovered by scientists in 1949, L-theanine is a non-protein amino acid which is unique compared to most other amino acids. It is also not recognised as an essential amino acid, meaning that your body does not require it to survive.

Theanine. C7H14N2O3 Amino Acid Analogue of L-glutamate and L-glutamine

L-theanine is becoming more recognized as a nootropic, as there is evidence it places a role in enhancing your brain health. It helps boost your cognitive function and alertness.

L-theanine comes from tea leaves, and is mainly found in green and black tea. It can also be found in smaller amounts in mushrooms. Interestingly, green tea has been used to instil calm and relax our brains for thousands of years. It wasn’t until 1949 when the compound of L-theanine was actually recognised scientifically.

With the benefits it has shown to have on people’s brain function, L-theanine is also known for increasing the calming neurotransmitters in our body. The impact of this has shown that L-theanine helps people to relax, ease anxiety and decrease their stress. Collectively, the symptoms that it helps reduce means that it has a positive impact on a person’s overall health and wellness.

Here are some of the health benefits that L-theanine has been said to have:

  • Enhance sleep
  • Boost immunity
  • Reduce stress and anxiety
  • Manage blood pressure
  • Improve cognitive function
  • Boost memory
  • Reduce neurological degenerative disorders

Anxiety explained

Anxiety is a natural response our body creates when we feel under threat. It is something we feel when we are worried about things that have happened, about to happen, or that we think might happen in the future.

It can affect the way we feel and the way we think, and also cause us to have physical symptoms.

It is normal for people to experience anxious feelings. When we are going through changes or stressful events in our life, we can experience a high amount of stress and anxiety. However, if this anxiety begins to impact your day-to-day life and you are unable to experience life as you would like to, then seeking help and adapting your lifestyle and mindset is crucial to no longer feeling this way.

There are many changes you can make to ease anxiety. This can be through lifestyle changes, nutritional changes, and for some, medication will help as well. If you feel you need extra support with coping with anxiety, then you must go and see your healthcare provider.

How does L-theanine help anxiety?

L-theanine behaves as an anxiolytic. Anxiolytics are medications used to treat or prevent anxiety symptoms or disorders. These medications are known to address anxiety very quickly and tend to only be prescribed for short-term use. This is to avoid addiction and dependency issues.

Due to L-theanine being a natural form of an anxiolytic, it is being studied to see how well it can be used to aid anxiety and stress. It has been found that adults who have taken or consumed L-theanine for a period of four weeks showed a significant improvement in their symptoms.

Let’s take a look at how L-theanine benefits our anxiety and stress levels.

L-theanine and Neurotransmitters

It is thought that L-theanine increases the levels of neurotransmitters which are responsible for altering our mood. Neurotransmitters are chemical messengers that your body needs to function. Their job is to carry chemical messages from one cell to another.

smiley face indicating happy mind

L-theanine can increase the levels of serotonin, dopamine and GABA. GABA stands for Gamma-Aminobutyric Acid, and this neurotransmitter has a calming effect on your body.

When we’re stressed or feeling anxious our brain can release excessive glutamate levels. Glutamate is known as an excitatory neurotransmitter. We need this when we sometimes want a quick release of energy. However, when we’re suffering with anxiety this can increase too much and leads to high blood pressure, increased heart rate and higher levels of stress hormones.

By consuming L-theanine it will increase our levels of GABA. When GABA is high, glutamate levels lessen, creating a calming and relaxing effect being released in the brain and body.

Whilst it hasn’t yet been proven, it is thought that L-theanine can increase our levels of serotonin and dopamine. Serotonin is known as the happy hormone that can make us feel positive and uplifted. Dopamine is responsible for our feeling of pleasure. Both of these neurotransmitters alter our mood, and if we are low in these it can bring on feelings of anxiety and depression.

L-theanine and Brain Waves

It has been shown that L-theanine helps to produce alpha waves in the brain. A brain wave is generated when a group of neurons send an electric signal to another group of neurons. There are five different types of brain waves, and within these waves they vary in speed. Each brain wave indicates a level of activity in the brain.

An alpha brain wave is produced when you are in a calm and relaxed state. Therefore if you are suffering from an anxiety disorder, it is beneficial for you to produce more of these calming brain waves.

If you’re able to generate alpha brain waves it can reduce your stress level and help you feel calm and rested.

Improved Memory

If you were to combine L-theanine with a small amount of caffeine, it has been shown that this can improve your memory as well as increase your reaction time. This is due to the calming effects of the L-theanine working with the stimulant from caffeine. This also helps increase your attention and ability to focus.

When you are suffering with anxiety, knowing that you are finding it hard to concentrate or you are struggling to remember information can cause you extra anxiety and panic. Therefore, this combination can be of benefit to some.

Blood Pressure

If we are feeling stressed or anxious our blood pressure will naturally rise. Particularly if we have a job where we are required to complete intense tasks, or work to a near impossible deadline.

If we have been feeling anxious or stressed for a prolonged period of time then it could be likely that we are suffering with high blood pressure as well. However, it is also possible that if you are suffering with a high blood pressure problem, such as hypertension, then that in itself could be triggering the anxiety.

L-theanine helps to reduce our nervous system’s response to stress. It is said that it can help produce nitric oxide which is a compound that helps dilate blood vessels and reduce your blood pressure. By helping to lower your blood pressure, this can have a positive knock-on effect and act as a nootropic to reduce anxiety.

If you take medication to manage high blood pressure, you would need to be cautious with consuming theanine. Speak to your healthcare provider regarding this.

Where can you get L-theanine from?

Unfortunately there are not many food sources available that are rich in L-theanine.

green tea leaves on a bush

Tea is the most natural source of L-theanine. You can get L-theanine from green tea and black tea leaves. Introducing a soothing cup of tea is a good step to including it in your diet. A 200 ml cup of green or black tea would give you a good dose of L-theanine to try out and see its impact.

We now know that some of the benefits of including L-theanine are relaxation and focus. By forming a daily habit of drinking tea for this reason will not only help with this, but it will also create a calming ritual of stopping to take a moment. This is really important for someone who is anxious.

It is always important to check the source of the tea that you are drinking. For example, if you are wishing to try green tea, you must ensure that this is not from green tea extract, as this may potentially not include any L-theanine.

Another source of L-theanine is from mushrooms. However, it is thought to be in very small amounts and may not be enough for any benefits to be felt.

L-theanine Supplementation

Another option is to take L-theanine as an oral tablet. There are many different options out there, so make sure to do your research. It is also recommended that before you take any supplement, seek advice from your healthcare provider.

It has been said that some individuals can feel calmer within 30 minutes of taking an L-theanine supplement.

Whenever you are considering taking a supplement to help with anxiety, it is really important to introduce lifestyle changes as well. This is in case the supplement does not suit you, you have still made positive changes that can help reduce anxiety and stress.

Lifestyle changes to consider:

Move your body: One way to naturally produce serotonin is to exercise. Not only would exercise benefit your mood, it also has many health benefits for your overall body.

Meditate: Meditation helps to relax your mind as well as your body. It also helps generate the alpha brain waves which help to create a calming and rested feeling.

Healthy diet: Ensuring you are eating a varied and nutrient-rich diet will benefit not only your physical health, but also your mental health.

Is there a ‘right’ time to take it?

Depending on the reasons you are deciding to add L-theanine to your diet, there may be benefits to taking it at a certain time in the day.

If you are looking to improve your cognitive function and boost your focus and energy, you could try consuming L-theanine in the morning. This would be the ideal time to combine caffeine and theanine together.

If you are wanting to reduce your anxiety, and with that improve your sleep, you may wish to consume it in the evening. It would not be recommended to mix it with caffeine later in the day, as this will affect your quality of sleep and perhaps cause stress and anxiety to rise.

Side effects of L-theanine

If you decide to take L-theanine as a supplement, then as with any new supplements you may wish to take, you must always proceed with caution. Consider any current medication or other supplements you may be taking, and seek advice from your healthcare provider.

clear tea cup of green tea loose leaves

Currently, there are no reported side effects to theanine. Many of us will already drink tea, as it is a well-established daily habit. Therefore, introducing a natural tea such as green tea (not the extract) could be a welcomed addition to your diet.

It is important to note that green tea does contain caffeine. It can also cause some stomach upset and nausea. If you haven’t had green tea before, it is worth introducing it gradually and monitoring any side effects it might have. You could also look to try decaffeinated green tea.

If you were to choose to consume L-theanine with caffeine, then you would need to be aware of the daily recommended intake of caffeine. This is said to be 400 mg for the average adult.

Side effects of consuming a high amount of daily caffeine can be:

  • Nausea
  • Headaches
  • Palpitations
  • Disturbed sleep
  • Irritability
  • Upset stomach

When you are suffering with anxiety, your consumption of caffeine must be considered and moderated. This is also important for pregnant women, if you are breastfeeding or suffering with a chronic life-threatening illness.


There does appear to be benefits to trying L-theanine to help manage anxiety. Although it isn’t officially recommended as a treatment, swapping out a coffee for a green tea would be a positive dietary change for most.

Combining lifestyle changes with dietary changes will help to ease symptoms. Anxiety can feel very overwhelming and it is important to seek support if you feel you are unable to cope.