L-theanine can be found naturally in plants such as tea and some mushrooms
As an amino acid, L-theanine increases relaxing brain chemicals and inhibits stress-related chemicals
The connection between L-theanine and sleep is that it helps you relax to prepare for sleep
L-theanine is generally considered safe with no side effects
You might already be familiar with melatonin as a natural sleep aid, but have you heard about L-theanine and sleep? This non-protein amino acid is found naturally in tea leaves and some mushrooms. 
Although more research is needed, small-scale studies found a variety of L-theanine health benefits, especially in relation to L-theanine stress benefits and supporting sleep For instance, studies show that L-theanine may relax the mind without causing drowsiness. [2,3,4] L-theanine may also help lower acute stress in people experiencing stressful situations. 
Thanks to these benefits—especially the ability to promote relaxation—L-theanine is more commonly being added to supplements designed to calm you and give you a good night’s sleep.
Interested in learning more about L-theanine sleep benefits? Let’s dig into what the research says.
Can L-Theanine Help You Sleep?
To understand L-theanine sleep benefits, it helps to know how this amino acid works in the body, particularly the brain. The appeal of L-theanine stems from its ability to relax the body and mind without sedating it.
Researchers think L-theanine may raise calming neurochemicals while at the same time lower stimulating ones.  More specifically, L-theanine boosts the brain’s production of serotonin, dopamine, and perhaps GABA as well.  Known as “happy hormones,” serotonin and dopamine play a role in regulating sleep, emotion, mood, alertness, and other body processes.  And GABA plays an inhibitor role by blocking or slowing down nerve signals, affecting how people may experience anxiety, fear, and stress.
So, while L-theanine elevates calming brain chemicals, it also triggers the release of the brain’s alpha waves, a marker of relaxation that’s linked to a feeling of wakeful relaxation similar to when you’re meditating.
Known as an anxiolytic, L-theanine helps to enhance relaxation and stress reduction, but it does so without sedating you. 
When Should You Take L-Theanine For Sleep?
Sometimes you might need help feeling less stressed, while other times you might need help sleeping. Therefore, when you take L-theanine depends on the problem you’re trying to solve.
So, should you take L-theanine in the morning or at night?
If you’re looking to get a good night’s sleep, take L-theanine at night. For example, if you need help getting to sleep, you won’t want to drink caffeinated tea at night, so you should opt for caffeine-free or herbal tea before bed. Or, you might consider taking a night-time supplement designed to promote better sleep. Try Nature Made Sleep Longer,™ which combines melatonin, GABA, and L-Theanine to help relax your mind, fall asleep faster, and stay asleep longer.
Can you take L-theanine and melatonin together? Yes, they both work differently in the body and can be taken together. But choose a supplement specifically designed with just the right amount of each ingredient to promote better sleep, whether you need help falling asleep or getting back to sleep if you wake up.
If you’re looking to calm down, but not necessarily go to sleep, consider taking a specially formulated stress supplement in the morning or as needed during the day. L-theanine is often paired with other ingredients (such as caffeine to boost alertness or melatonin to promote sleep), so consider taking Nature Made’s Clear & Focus, which contains caffeine if you need to relax and focus, or Nature Made’s Stress Relief gummies, which blends L-theanine and chamomile to help you manage stress in the moment.
See the graphic below to see how much sleep is recommended by age.
What are the Side Effects of L-Theanine?
In general, L-theanine is well tolerated by healthy adults and considered safe. However, due to the caffeine content in teas, consuming large amounts can lead to nausea, upset stomach, and irritability. 
Is L-Theanine Safe for Long-Term Use?
As long as you follow the L-theanine supplement’s dosage suggestions, you can safely take L-theanine daily. And because L-theanine is a 100% drug-free, non-habit-forming ingredient, it is generally considered safe for long-term use. As always, if you’re pregnant, breastfeeding, or taking medication, consult with your doctor before taking any supplements.
L-theanine is an amino acid that occurs naturally in plants such as tea and some mushrooms. It works in the body by increasing calming brain chemicals and inhibiting stress-related chemicals. L-theanine may help support relaxation and sleep without sedative effects. It is well tolerated by most healthy adults and generally considered safe with no side effects. Along with healthy sleep habits and stress reduction techniques, L-theanine can be another tool in your wellness box to help you manage stress and support better sleep.
Continue to check back on the Nature Made blog for the latest science-backed articles to help you take ownership of your health.
This information is for educational purposes only and is not intended to serve as medical advice. Consult your healthcare provider for more information.
† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
Journal of Agriculture and Food Chemistry. “From Tea Leaves to Factories: A Review of Research Progress in l-Theanine Biosynthesis and Production.” January 21, 2021. Accessed on: January 10, 2022. https://pubs.acs.org/doi/10.1021/acs.jafc.0c06694
Lisa Beach is a seasoned journalist whose work has been published in The New York Times, Good Housekeeping, Eating Well, Parents, AARP’s Disrupt Aging, Optimum Wellness, and dozens more. She also writes for a variety of health/wellness-focused brands. Check out her writer’s website at www.LisaBeachWrites.com.
As a member of the Medical and Scientific Communications team, Sandra educates healthcare professionals and consumers on nutrition, supplements, and related health concerns. Prior to joining Pharmavite, Sandra worked as a clinical dietitian at University of Chicago Medicine in the inpatient and outpatient settings. Sandra received her Bachelor of Science degree in Nutritional Science, with minors in Spanish and Chemistry from the University of Arizona in Tucson, AZ. She earned her Master of Science degree in Clinical Nutrition from RUSH University in Chicago, IL. As part of her Master’s program, Sandra performed research on physical activity participation and correlates in urban Hispanic women.