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Last updated: September 2026.
The short answer
L-theanine and CBD are both natural supplements people take to feel calmer, but they work in different ways. L-theanine, an amino acid from tea, tends to give a “relaxed but alert” feeling and is popular for calm focus during the day. CBD, from hemp, is more often used to wind down and as part of an evening routine. Neither is “better”: it depends on what you want. They can also be taken together, and there is no known interaction between them.
L-theanine vs CBD at a glance
| L-theanine | CBD | |
|---|---|---|
| What it is | An amino acid found in tea leaves | A compound from the hemp plant |
| How it works | Increases calm, “alert” alpha brain waves and affects calming brain chemicals such as GABA | Works with the endocannabinoid system, which helps regulate mood, rest and stress |
| Typical amount | 100 to 400mg a day | 15 to 50mg a day |
| Felt within | 30 to 60 minutes | 15 to 60 minutes (oil under the tongue) |
| Makes you sleepy? | Usually not; “relaxed but alert” | Can make some people drowsy at higher amounts |
| Popular for | Calm focus, taking the edge off coffee | Winding down, stress, sleep routine |
What is L-theanine?
L-theanine is an amino acid found mainly in green and black tea. A cup of tea contains roughly 10 to 30mg. It is a big part of why tea feels calming in a way coffee doesn’t, even though both contain caffeine. As a supplement it is usually sold as capsules, powders or gummies containing 100 to 200mg per serving.
Research on L-theanine is small but consistent. A 2008 study found 50mg increased alpha brain wave activity, a pattern linked with relaxed alertness (Nobre et al., 2008). In a 2019 trial, 30 healthy adults who took 200mg a day for four weeks reported lower stress-related symptoms and better sleep quality than with placebo (Hidese et al., 2019). Paired with caffeine, it has also been shown to improve attention in some studies (Owen et al., 2008).
What is CBD?
CBD (cannabidiol) is a natural compound from the hemp plant. It does not cause a “high”. It works with the body’s endocannabinoid system, a network of receptors involved in keeping the body in balance. Most people take it as an oil under the tongue. Our 10% CBD oil gives 5mg per drop, and most people start with around 25mg a day.
In a 2019 case series of 72 adults, most reported lower anxiety scores within the first month of taking CBD, and about two thirds reported better sleep at first (Shannon et al., 2019). Small controlled studies have also found CBD reduced anxiety during stressful tasks such as public speaking.
L-theanine vs CBD: which should you choose?
- For calm focus at work or study: L-theanine is the more common choice, especially alongside your morning coffee.
- For winding down in the evening: CBD is the more popular option, often as part of a bedtime routine.
- For everyday stress: both are used. Some people prefer L-theanine by day and CBD in the evening.
- If you want to avoid any chance of drowsiness during the day: start with L-theanine, or take CBD in the evening only.
L-theanine vs CBD for anxiety
Both have small studies suggesting they may help with everyday stress and anxious feelings, and neither is a treatment for an anxiety disorder. If you have been diagnosed with anxiety or take medication for your mood, speak to your GP before trying either.
Can you take L-theanine and CBD together?
Yes. For most healthy adults, L-theanine and CBD can be taken together, and there is no known interaction between them. No study has tested the combination directly, so the usual advice applies: start with a low amount of each, add one at a time, and see how you feel before driving if you notice any drowsiness.
Popular ways to combine them:
- L-theanine in the morning, CBD in the evening. Calm focus by day, wind-down at night.
- Both in the evening. For people whose main goal is a calmer end to the day.
- Both before a stressful event, such as a presentation or exam, once you know how each one affects you.
L-theanine and CBD interaction and safety
Both are well tolerated by most people. L-theanine rarely causes side effects but may slightly lower blood pressure. CBD can cause tiredness, a dry mouth or an upset stomach in some people, and it can interact with medicines processed by the liver’s CYP450 enzymes, including blood thinners. Speak to your doctor or pharmacist before combining them if you:
- Take any regular medication, especially for blood pressure, blood thinning, epilepsy or mood
- Take sedatives or sleeping tablets
- Are pregnant or breastfeeding
For more on CBD and blood thinners, see does CBD oil affect blood clotting?
L-theanine and CBD gummies
Some brands sell gummies that combine both. They are convenient, but check the label for how much of each is in a gummy, as amounts are often low. Taking them separately lets you adjust each one. If you like gummies, our CBD gummies contain 15mg of CBD each, and you can pair them with your own L-theanine.
Where L-theanine comes from: your cup of tea
L-theanine is an amino acid found naturally in tea leaves. It is one reason a cup of tea can feel calmer than a cup of coffee, even though both contain caffeine. A cup of green or black tea typically contains somewhere between 5mg and 30mg of L-theanine, depending on the tea and how long you brew it. Supplements usually contain much more, often 100mg to 200mg per capsule.
If you drink several cups of tea a day, you are already getting some L-theanine. Supplements simply give a larger, more consistent amount.
A simple daytime routine with L-theanine and CBD
Many people use the two at different times of day rather than together. One routine our customers like:
- Morning: coffee or tea, with L-theanine if you find coffee leaves you jittery.
- Afternoon: a few drops of 10% CBD oil or a CBD gummy to keep the rest of the day steady.
- Evening: a calmer wind-down without caffeine, with CBD as part of your routine if you like.
Start with one product at a time, so you know how each affects you, before combining them.
How to choose an L-theanine or CBD supplement
For L-theanine, look for a product that clearly states the amount per capsule and lists few other ingredients. For CBD, look for the amount of CBD in mg, a batch lab report and an Irish or EU company behind the product. Whichever you choose, avoid products that promise to treat anxiety or any other condition. Food supplements cannot make those claims, and a seller that does is cutting corners.
Frequently asked questions
Is L-theanine or CBD better for sleep?
CBD is more commonly used as part of an evening routine. L-theanine has one small study showing better sleep quality over four weeks. Some people take both. For sleep, you may also like our guide to CBD and magnesium.
Does L-theanine make you tired?
Usually not. Most people describe it as calm but alert, which is why it is popular with coffee.
Can I take L-theanine, CBD and coffee together?
Many people do. L-theanine is often taken with coffee to smooth out the caffeine. If you add CBD, start low and see how the combination feels.
How much L-theanine should I take with CBD?
Studies have mostly used 100 to 400mg of L-theanine a day. With CBD, most people start around 25mg a day. Begin at the lower end of both.
Does CBD contain caffeine?
No. CBD contains no caffeine. If you take a CBD product with coffee or tea, the caffeine comes from the drink.
Can I get enough L-theanine from green tea?
Tea gives you a small amount of L-theanine in each cup. If you want the larger amounts used in supplements, you would need to drink a lot of tea, along with a lot of caffeine, which is why some people prefer a supplement.
Can I take L-theanine and CBD gummies at night?
You can, but if you take L-theanine as part of a caffeinated drink in the evening, the caffeine may keep you awake. Most people keep caffeine to the morning and early afternoon.
Buying CBD in Ireland
Dr. Hemp Me has been serving Irish customers since 2018 and has looked after over 15,000 customers. Every batch of our CBD oil is independently lab tested, and orders placed before 2pm are dispatched the same working day for next-day delivery in Ireland. See our dosing guide to get started.
Disclaimer: CBD and L-theanine are sold as food supplements. They are not intended to diagnose, treat, cure or prevent any disease and are not a substitute for medical advice. Always consult a healthcare professional before starting a new supplement, especially if you take medication, are pregnant or breastfeeding.
References
- Nobre, A.C., Rao, A. and Owen, G.N. (2008) “L-theanine, a natural constituent in tea, and its effect on mental state.” Asia Pacific Journal of Clinical Nutrition
- Hidese, S. et al. (2019) “Effects of L-theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial.” Nutrients
- Owen, G.N. et al. (2008) “The combined effects of L-theanine and caffeine on cognitive performance and mood.” Nutritional Neuroscience
- Shannon, S. et al. (2019) “Cannabidiol in anxiety and sleep: a large case series.” The Permanente Journal
