L-theanine for sleep

When you’re looking to sleep better, there are a wide variety of approaches you can take. Whether you try nighttime yoga to relax, meditate, or turn off that iPhone before you crawl into bed, you have a multitude of options when it comes to sleep routines. 

One of the most common approaches utilizes natural sleep aids that boast botanical ingredients from the East or West and amino acids like, L-theanine. 

L-theanine is an amino acid found in green and black tea leaves, as well as Bay Bolete mushrooms. It’s been identified as beneficial for quality of sleep by enhancing relaxation. When paired with caffeine, it also promotes mental focus. 

So, how can you incorporate L-theanine into your evening routine to get better quality sleep? This amino acid is commonly found in a multitude of supplements that aim to reduce anxiety, stress and promote relaxation. 

As you are probably aware, green and black tea naturally contain caffeine. So beware that drinking these teas to access the relaxing effects of L-theanine is counterproductive. While L-theanine synergizes nicely with the effects of caffeine, the sleep-enhancing effects of natural L-theanine are offset by the tea’s natural caffeine.

At Remrise, we’ve incorporated L-theanine as part of a blend of natural sleep aids and we’ll go through why below.

L-theanine dose for sleep

The recommended dose range when using L-theanine for sleep is between 100 and 400mg. 

As a supplement, L-theanine becomes effective within 30 minutes of taking it. Its effects can be felt for up to five hours. Remember, that you can always increase your dose, so you should start out with the smallest level. 

L-theanine benefits

Improved sleep is one of the main reasons that people take L-theanine because of its ability to promote relaxation and not cause drowsiness. L-theanine does not work like a sedative, instead, it lessens anxiety and improves mood — ultimately facilitating relaxation. Some of the most common contributing benefits of L-theanine are:

Reduced anxiety and stress

L-theanine is an anxiolytic, meaning it reduces anxiety. There are other anxiolytics that work more as sedatives such as hops and valerian. But L-theanine also reduces stress and improves relaxation, without sedation. Many studies show that L-theanine enhances alpha brain waves, a frequency of brain activity associated with wakeful relaxation. Alpha waves are most commonly associated with meditative states.

L-theanine is thought to work in part by increasing GABA levels in the brain, a neurotransmitter that is involved in inhibiting activity in the brain. Additionally, the L-theanine molecule blocks glutamate receptors. Glutamate is one of the main excitatory neurotransmitters in the brain, so this reduces brain activity as well.[1] Taken together, these mechanisms result in L-theanine’s anti-anxiety effects and helps to alleviate psychological stress.

L-theanine promotes parasympathetic responses in the body as well, which can help alleviate physiological stress responses. L-theanine has been shown to lower blood pressure and resting heart rate. Those that experience anxiety and stress can benefit from incorporating L-theanine into their lives, which may then lead to better sleep.

Improved focus and memory

When you are stressed out, your body produces stress hormones like cortisol. This hormone can negatively affect your memory as well as your general cognitive function. L-theanine works to lower these levels so that there is no interference with your learning or memory.

Improved cognitive skills

It has been shown in studies to increase the reaction time and attention span in people that suffer from anxiety, resulting in improved accuracy while under highly stressful situations like test-taking.

Healthy weight management

Having the proper amount of sleep at night can help maintain a healthy weight.

This is further benefited by supporting a healthy metabolism that works in concert with maintaining a healthy diet, thus reducing the potential for weight gain.

L-theanine side effects

The research about the side effects of theanine is limited because negative effects are not substantiated. However, people with cancer should not take this supplement. Green tea has polyphenol EGCG which can lower the efficacy of chemotherapy drugs. So, if you’re taking these types of drugs it’s important to speak to a doctor before introducing supplements that could have interactions.

Those that suffer from low blood pressure must also be careful when taking L-theanine. As a rule of thumb, it’s always best to seek medical advice before taking supplements with a medical professional if you have any health conditions. 

L-theanine for anxiety

Since anxiety is one of the most common causes of secondary insomnia symptoms, reducing anxiety can make a big impact towards improved sleep quality. There isn’t a designated dose that you should take for anxiety. However, those that suffer from mild anxiety take between 50 to 200 mg of L-theanine a day. 

You will continue to feel the effects of the supplement for eight to 10 hours. Those with moderate anxiety will often take a higher dosage of 200 mg up to twice a day.[1

Also, there is no risk that you will become dependent on L-theanine. 

How L-theanine and caffeine work together

Taking L-theanine with caffeine isn’t the way you’re going to get to sleep, but it can be helpful in other areas of your life. When you drink coffee in the morning, it can really jumpstart your day. However, coffee can also make you feel really anxious and jittery. 

So, when you incorporate L-theanine supplements with your caffeine or drink caffeinated tea, you get the best of both worlds. L-theanine reduces your anxiety and stress levels, so it can bring a sense of balance, smooth out the jitteriness, and minimize the feelings of stress while you are caffeinated. 

L-theanine also helps blood flow more freely throughout your body, while you have caffeine in your system. Caffeine is a vasoconstrictor, which means it restricts blood vessels in your body. L-theanine prevents caffeine from doing this. There are also fewer headaches and caffeine crashes when using L-theanine. 

L-theanine supplements

L-theanine isn’t made by the body, so it’s only accessible by taking dietary supplements or drinking tea. Supplemental L-theanine readily crosses the blood-brain barrier and is thought to have a bioavailability between 47% and 54%.[3] When you take L-theanine, make sure to check the label on any natural supplements that you buy to make sure there aren’t unhealthy fillers. 

Also remember that most teas will have caffeine, compared to an L-theanine supplement that doesn’t. If you’re looking to improve your sleep with L-theanine, make sure that you do so with supplements rather than tea.

At Remrise, we believe L-theanine is most effective in facilitating healthy sleep when it is blended with other supplements. Remrise’s sleep formulations cycle L-theanine on days three and seven. It is paired with several other ingredients in a complementary manner to create a synergistic effect. 

For example, it’s functioning alongside L-tryptophan, which is an amino acid and precursor to melatonin, a hormone necessary for regulating sleep cycles. These amino acids are benefitted by two botanicals: passionflower and hops. Both of these are known to calm the nervous system and promote relaxation, but through their sedative-like properties, which differ from L-theanine’s mechanism of action. 


Anxiolytic: Any drug or other intervention that reduces anxiety symptoms.


  1. Nathan PJ, Lu K, Gray M, Oliver C. The neuropharmacology of L-theanine (N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother 2006;6(2):21–30.
  1. Lake, J. (2017, March 15) L-Theanine Reduces Symptoms of Anxiety. Retrieved from https://www.psychologytoday.com/us/blog/integrative-mental-health-care/201703/l-theanine-reduces-symptoms-anxiety
  1. Scheid L, Ellinger S, Alteheld B, Herholz H, Ellinger J, Henn T, Helfrich HP, Stehle P. Kinetics of L-theanine uptake and metabolism in healthy participants are comparable after ingestion of L-theanine via capsules and green tea. J Nutr 2012;142:2091–6.