I wasn’t actually planning on writing this article, as I hoped this information was already out there to benefit myself.
But to my disappointment, it wasn’t.
So to find the truth to this question, I decided to be the guinea pig of my own little experiment.
That’s right…
For 2 weeks straight, I’d taken 200mg of L-Theanine every single day.
(To ensure this was a fair experiment, I stopped taking all of my other supplements.)
On Mondays, Wednesdays, Fridays and Sundays, I’d take 200mg in the morning alongside my fresh ground coffee.
On Tuesdays, Thursdays and Saturdays, I’d take 200mg in the evening around 1 hour before going to sleep.
For me, this 2 week period was enough to notice the effects of L-Theanine, and how it made me feel in the morning and evening…
…and my conclusion pretty much matched my prediction:
The best time of day to take L-Theanine depends on the desired effects you want from it.
Some people are better suited to taking L-Theanine in the morning, whereas others are better off taking it in the evening.
This is based off both my experience as well as solid science to back it up.
So hopefully by the end of this article, you’ll know exactly which camp you’re in.
Team morning, or team evening?
Let’s go!
Reasons To Take L-Theanine In The Morning
1. L-Theanine Helps Reduce Caffeine Jitters

I’d be lying if I said my favourite time of day was anything other than that first sip of a warm, aromatic coffee.
You know…
The one which makes you go “Mmm” in delight.
Nothing compares.
But what I really can’t stand about coffee is its unpredictability.
Some days it makes feel in the zone, helping me focus and making me more alert.
Whereas other days, this caffeine kick can be overwhelming.
Jitters, headaches, anxiety are just a few of the effects of too much caffeine.
And it sucks.
I’d say roughly half of the coffee I drink gives me the desired effects, whereas the other half makes me feel really on edge.
But since taking L-Theanine alongside my morning coffee, I have only noticed the desired effects being amplified with no signs of too much caffeine!
2. L-Theanine Improves Cognitive Function
You may be thinking: How on earth can the positive effects of coffee be amplified, whilst the nasty side effects are gone? Surely it’s the caffeine that makes you feel alert and focused?
Well it turns out L-Theanine acts as a nootropic – a fancy way of saying a “smart drug”.
(Before you panic at the word “drug”, L-Theanine is 100% legal.)
It works as a nootropic by amplifying your Alpha brain waves, which are responsible for heightened creativity.
So by taking L-Theanine in the morning, you’ll be able to get more done in the office during the day, finish your essay on time or beat the world record for solving a rubix cube.
(Okay… maybe not the last one.)
3. L-Theanine Helps Reduce Anxiety
If you’re unfortunate enough to suffer from anxiety, then chances are, you’ve heard of Xanax and Valium.
But for those who don’t know, these are the drugs given to help relieve anxiety symptoms.
Unfortunately, like many prescription drugs, they have a lot of unwanted nasty side effects, including dizziness, nausea and drowsiness.
Both Valium and Xanax are effective at treating anxiety by increasing a chemical in the brain called Gamma-Aminobutryic acid aka GABA.
What’s great about L-Theanine is that it also increases GABA, without the nasty side effects of prescription drugs.
Whilst I don’t suffer from anxiety myself, taking L-Theanine in the morning would be one of my first lines of defence against the mental disorder.
Disclaimer: My personal preference is to always seek “Natural” ways of treatment before going down the medical route. I wouldn’t necessarily recommend you do the same.
(Related reading: L-Theanine vs GABA)
Reasons To Take L-Theanine In The Evening
By now, you may have already made your mind up and decided that L-Theanine is a perfect addition to your morning routine.
But for those who are still in on the fence, this section of the article covers the benefits of taking L-Theanine in the evening.
1. L-Theanine Helps Improve Sleep

The regular Vitalized Future readers will know by now just how much good quality sleep means to me (and should mean to you).
For the last 6 months, my sleep quality has been amazing, and I credit this to supplementing with Phosphatidylserine (PS) and Holy Basil, as well as decreasing my use of screens before bed.
So when I started this experiment (and hence stopped supplementing with PS and Holy Basil), I was a little bit nervous to say the least.
Swapping the tried and tested PS and Holy Basil for the unknown L-Theanine was a risky move…
…but I’m so glad I tried it.
My sleep quality was as good as ever, and giving my body a rest from other supplements probably done me the world of good.
This stuff will help you sleep better if you take it in the evening.
Trust me.
I judge my sleep quality on the following 2 variables:
- How deep my sleep is
- How fast I’m able to fall asleep
L-theanine seems to improve sleep in both of these ways.
First, it helps you fall asleep faster by calming your mind, lowering anxiety and hence reducing overthinking.
Then, it helps you enter a deep state of sleep by increasing alpha brain waves.
(Related reading: Do Cold Showers Help You Sleep?)
Conclusion
By reading this article, you now have all the information you need to decide whether you’re best suited to taking L-Theanine in the morning or evening.
I’m sure some of you are thinking: Can I not take it in both the morning and evening? so I’ll quickly give my 2 cents’ worth now…
Taking it in both the morning and evening will result in you taking more L-Theanine in a 24 hour period.
Whilst you’re very unlikely to take too much, the fact that you’re taking more will increase your tolerance to it.
This means you’ll need to take more and more to feel the intended effects.
So for this reason, I personally wouldn’t take L-Theanine in both the morning and the evening.
As for myself?
I’m in team morning!
Thanks for sticking to the end and let me know your thoughts in the comments below.
I found this article /your experience very helpful – thanks for sharing !
Thanks Patti 🙂
I’m really glad you enjoyed it!
Robb
So you are saying “not” to take L-theanine in the eve alongside PS and Holy Basil?
I currently take PS. Was actually thinking of adding HB AND L-theanine.
Hi Sherry,
As I’m not a certified doctor, I can’t recommend specific combinations for people unfortunately.
However, I personally don’t see a problem with taking them all in the evening.
Robb
Thank you for the information. It made it easier for me to make a decision. Since you take L theanine in the morning, what helps you get better sleep at night? Did you get back to taking PS and holy basil in the evening?
You’re welcome Juan, glad it helped!
Yep, back to PS and Holy Basil in the evening.
But I sometimes rotate between the 3 in the evening so I don’t build a tolerance.
i can’t believe it. i evidently have anxiety, and overthink things big time, and cry at everything, good things.. had l-theanine in my cupboard, took 2-100mg. yesterday, and within 2 hrs., NO more crying!! i believe in natural not pharmaceutical, pharm has way to many side affects, FDA – yea right! WRONG. i’m a 62yr. old male taking NO medicine, except 2-aleve per day. these old bones (even with drinking almost 2 gallons of milk per week) need a little help. thank you for clarifying some points, i’ll go for the morning routine.
Hey Marc,
I’m so pleased that L-Theanine is working for you!
And I’m glad you enjoyed the article 🙂
Your body cannot absorb calcium without vitamin D. Not sure where you live, but if it’s north of Kentucky, you’re probably deficient. Typically, a multivitamin will not be enough either. Have your D tested. On average, people supplement 2,000 – 4,000 Int’l Units daily, just to stay in recommended range. I’m a big advocate of supplementing vitamin D. Wish I had learned of this earlier in life!
I’ve been taking l-theanine for just a couple days. At night. Got up this morning wondering if I should take it in the morning and found your article and it answered every single one of my questions! I’m not going to take it today or I might have too much in my system. I’m about 115 lb I don’t want to overload …. I will skip today, and tomorrow I’m switching to morning’s! Thank you I will report back!
Hey Tammy,
I’m glad the article helped you!
Let me know how you get on 🙂
Robb
Thank you for all the information. I just started taking L-Theanine. 200 mg in the morning. It has helped the anxiety. How long does it last in your system? I was hoping it would last me thru the night. Any thoughts? Thank you
Hi Richard,
I’m so glad it’s helped your anxiety!
The honest answer is I really don’t know. You could maybe try taking it in the evening instead of the morning for a few days and see how you feel?
Robb
Hi Robb,
Great article thank you. Maybe I missed something, but on the days when you took L Theanine in the morning, did you also get a decent sleep that night too? I read something elsewhere where the writer said this was the case, as in regardless of what time they took it, it “improved” their depth and duration of sleep . Thank you.
Hi Kenneth,
I’m glad you enjoyed it!
My sleep was still pretty good on the days I took it in the morning, although I believed it was better on the days I took it in the evening.
Robb
Hi, I take l-Theanine and can second it’s anti anxiety benefits. However you made an error in your experiment, one which many people do. You wanted to use a clean plate and stop taking all of your supplements and only taking l-Theanine. However, by doing so you introduced many changes to your body that now interfere with the experiment more than if you had continued taking them.
Hi Dan,
That’s an interesting angle to look at the experiment, but doing it that way means you can’t tell if it’s the l-theanine working or the other supplements.
Robb
Just wondering if you could take 1 pill in the morning and 1 pill in the evening, would you still benefit with the cognitive function during the day and the sleep at night? Each pill contains 225mg of L-Theanine.
Hi Andrea,
There’s no harm in trying it and seeing if it works for you 🙂
But as advised in the article, the more L-Theanine you take the higher your tolerance will be.
Robb
Hi Robb,
This is what I wanted to know! But of course there is always that one person who wants to take L-Theanine in the afternoon… So, was wondering if your very specific experiment gave you any indications of whether taking it in the afternoon might make a person sleepy?
Thanks!
Addie
Hi Addie,
Thanks for your comment – that’s a great question!
It’s a tough one to answer since:
(a) I’ve never took it in the afternoon
(b) You’re biologically different to me
I don’t think there’s any harm in trying though. If you’re not usually tired in the afternoon, I’d have thought it’d make you feel calm, rather than sleepy.
Regardless, I guess the only way to find out is to bite the bullet and try it for yourself.
Robb
Thank you for your review! My doctor just prescribed L-Theanine for my anxiety, and I wasn’t sure when would be the best time to take it. So I just googled it and your review came up, and I’m glad I read it!
Glad you liked it!
Excellent article & very helpful! Thank you for sharing your experience. I think I’ll try morning first.
—- Dave
Thanks Dave, appreciate the kind feedback. Let me know how it goes!
This was very helpful – Thank you :)! Could you tell me if L-Theanin made you “sleepy” or did it just enhance your sleep (and the ability to fall into sleep). I’m a shift worker and I’m currently trying to figure out whats the optimal way to use supplements when having night shifts.
Glad you liked it Felix. It definitely made me more relaxed at night time, so you could say it made me “sleepy”.