Quick answer
NOW Foods lists both of its L-theanine capsules at 1 capsule 1 to 2 times daily as needed. The Double Strength 200 mg capsule says preferably on an empty stomach. The 100 mg capsule, which also contains decaf green tea, says to take it with food and not on an empty stomach. So a label day is 100 to 200 mg (regular) or 200 to 400 mg (Double Strength). Many people take it in the daytime with coffee or in the evening as part of a wind-down routine.
Key takeaways
L-theanine is an amino acid from tea that is generally described as calming without causing drowsiness.
Because of that, people use it at different times of day, and it is often paired with coffee to soften jitters.
Most human studies are small and short, and anyone who is pregnant, nursing or taking medication is wise to check with a clinician first.
If you have questions about whether L-theanine fits your plan, a short call is a simple place to start.
L-theanine is an amino acid found naturally in tea leaves. It is one of the most searched supplements for relaxation, focus, and sleep routines, and the most common questions are how much to take, when to take it, and what it can be taken with. This page summarizes the official NOW Foods label directions for its two L-theanine capsules, how people often time it, common pairings, and who should check with a provider first. It is educational information. For broader context, see Calming supplements for stress and Natural sleep aids: supplements and habits.
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Two NOW Foods L-theanine products, two sets of directions
- L-Theanine, Double Strength 200 mg. Each capsule has 200 mg L-theanine plus 100 mg inositol. NOW Foods label: take 1 capsule 1 to 2 times daily as needed, preferably on an empty stomach. It is also listed in the Fullscript catalog.
- L-Theanine 100 mg. Each capsule has 100 mg L-theanine plus 250 mg decaffeinated green tea leaf. NOW Foods label: take 1 capsule 1 to 2 times daily as needed, with food. Do not take it on an empty stomach, and do not exceed the recommended dose. It is also listed in the Fullscript catalog.
The difference in food directions comes from the labels themselves: the 100 mg product contains green tea leaf, and its label asks you to take it with food. Always follow the label on the bottle you have, since labels can change.
Label dosing at a glance
The Double Strength 200 mg product is 1 capsule, 1 to 2 times daily as needed, which works out to 200 to 400 mg per day. The regular 100 mg product is also 1 capsule, 1 to 2 times daily as needed, or 100 to 200 mg per day.
Both labels say adults only. Neither label lists a maximum number of weeks, so ask your provider how long it makes sense for you.
In research, doses are in a similar range. A systematic review of 9 randomized trials looked at 200 to 400 mg per day of L-theanine (Williams 2020), and a 4-week trial in healthy adults used 200 mg per day (Hidese 2019).
Morning or night?
L-theanine is generally described as relaxing without causing drowsiness, so it can fit either time of day. In EEG studies, L-theanine increased alpha brain wave activity, a pattern linked with a relaxed but awake state (Nobre 2008).
Daytime: many people take it with their morning coffee or before a busy stretch of work. Evening: others take it 30 to 60 minutes before bed as part of a wind-down routine, and in the 4-week Hidese trial, sleep quality questionnaire scores improved with 200 mg per day compared with placebo.
Twice daily: both labels allow up to 2 capsules a day, so some people split it between daytime and evening.
Start with 1 capsule and notice how you feel before adding a second. Please follow the plan your own clinician gives you.
Can I take L-theanine with other things?
These are the pairing questions people search most. The answers below are general, so check with your own provider, especially if you take medications.
Coffee or caffeine is a common pairing. In one placebo-controlled study, 100 mg L-theanine with 50 mg caffeine improved speed and accuracy on an attention-switching task compared with placebo (Owen 2008). With magnesium (including glycinate), there is no known label conflict, and many evening routines combine the two. See Magnesium glycinate vs citrate vs oxide vs L-threonate. Melatonin and L-theanine are both often used in evening routines, but ask your provider before combining sleep-related products, and avoid driving if you feel drowsy.
Ashwagandha or adaptogen blends are commonly combined with L-theanine in stress formulas. See Ashwagandha: morning or night? and Ortho Molecular Adapten-All and Reacted Magnesium: how to take them. If you take prescription medications, ask your prescriber or pharmacist first, especially for blood pressure medications, sedatives, or any medication that affects mood or sleep. The NOW labels say to consult a physician if you take medication.
Cautions and who should check with a provider
Both labels say adults only. Ask first if you are pregnant or nursing, take medication, or have a medical condition, and note that the 100 mg label also names liver disease. Take the 100 mg product with food, as its label directs.
If you feel unusually drowsy, avoid driving until you know how it affects you. Stop and contact your provider if you notice a negative reaction.
What the research says
Most human studies on L-theanine are small and short. A systematic review concluded that 200 to 400 mg per day may help people manage stress in stressful conditions, while noting that larger and longer studies are still needed (Williams 2020). A 4-week randomized crossover trial in 30 healthy adults found improvements in stress-related and sleep quality questionnaire scores with 200 mg per day (Hidese 2019). Research used L-theanine on its own, not these specific NOW products.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Would L-theanine fit with my current medications and the times of day I feel most tense?
Could L-theanine interact with any of my current medications or other supplements?
Would any labs or health history details help us decide whether L-theanine makes sense for me?
How would we tell whether L-theanine is a good fit for me, and when should we check in again?
Practitioner-grade options in my Fullscript catalog: if you and your clinician decide a supplement makes sense, my supplement guide by health goal links to the practitioner-grade products I trust.
Frequently asked questions
How much L-theanine should I take?
NOW Foods lists 1 capsule 1 to 2 times daily as needed for both its 100 mg and 200 mg capsules. That equals 100 to 200 mg per day with the regular capsule or 200 to 400 mg per day with Double Strength. Ask your provider what fits you.
Should I take L-theanine with or without food?
It depends on the product. The NOW Double Strength 200 mg label says preferably on an empty stomach. The NOW 100 mg label, which contains decaf green tea, says to take it with food and not on an empty stomach.
Is it better to take L-theanine in the morning or at night?
Either can work. L-theanine is described as relaxing without drowsiness, so some people take it with morning coffee and others take it 30 to 60 minutes before bed.
Can I take L-theanine with coffee?
Yes, this is a common pairing. In one study, 100 mg L-theanine with 50 mg caffeine improved performance on an attention-switching task compared with placebo.
Can I take L-theanine with magnesium glycinate?
There is no known label conflict, and many evening routines combine them. Check with your provider if you take medications.
Can I take L-theanine with melatonin?
Both are often used in evening routines. Ask your provider before combining sleep-related products, and avoid driving if you feel drowsy.
Can I take L-theanine with ashwagandha?
They are commonly combined in stress formulas. Ask your provider first if you take medications or have a thyroid or other health condition.
Can I take L-theanine with my prescription medication?
Ask your prescriber or pharmacist first, especially for blood pressure medications, sedatives, or medications that affect mood or sleep.
Related reading
- Calming supplements for stress
- Natural sleep aids: supplements and habits
- Magnesium glycinate vs citrate vs oxide vs L-threonate
- Ashwagandha: morning or night?
- Ortho Molecular Adapten-All and Reacted Magnesium: how to take them
- How to take Cortisol Manager
- Nootropics for brain health
Sources
- NOW Foods. L-Theanine, Double Strength 200 mg Veg Capsules: Supplement Facts, suggested usage, and caution.
- NOW Foods. L-Theanine 100 mg Veg Capsules: Supplement Facts, suggested usage, and caution.
- Williams JL, et al. The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review. Plant Foods Hum Nutr. 2020. PubMed 31758301
- Hidese S, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients. 2019. PubMed 31623400
- Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pac J Clin Nutr. 2008. PubMed 18296328
- Owen GN, et al. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008. PubMed 18681988
Talk with your own doctor or healthcare provider about the right dose for you before starting any supplement, especially if you’re pregnant, nursing, or take medications.
Browse my full Fullscript store
If you have questions about whether L-theanine fits your plan, a short call is a simple place to start.
This page shares general educational information and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Talk with your healthcare provider before starting any supplement, especially if you take medications, are pregnant or nursing, or have a health condition. Product labels can change, so always follow the label on the bottle you have.
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