Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count

I find this particular formulation of L-Theanine to be a very good adjunct to help me fall asleep and stay asleep. This formula by the Doctor's Best brand has "Suntheanine," which is a patented form of the amino acid L-Theanine known to promote relaxation. I've taken this formula steadily for about a year at bedtime with only good results as part of an overall sleep hygiene routine that also includes listening to a Calm sleep story on the app in my phone, next to my bed. Also why I like this particular formulation is that it has just 150 mg of the Suntheanine/L-theanine in it, which is less than most other formulas on the market. IMO, less of something often translates to "more." I don't know how long it stays in the system, but probably not for very long, because I wake up normally, with no leftover drowsiness. Another reason why I like this supplement is because it's NON-hormonal. Some folks use melatonin to promote sleep, but I've always avoided that, since melatonin is a hormone, and from what I understand, it's not meant to be used long-term. For me, this has performed as a safe and effective over-the-counter sleep aid. As of December 2025, it was still reasonably priced.

Really does work for anxiety, as someone who suffers from anxiety and been on a lot of prescription medication thus L-Theanine is almost as good, take as directed and give it some time, helped me during a Benzo taper.

This supplement really helps with calm focus. I take it in the morning with coffee and it removes any nervous edge from caffeine. Clean product, no aftertaste, works exactly as expected.

Suntheanine, so far, has been a really great supplement to have handy. I have been using it regularly for 3-4 months as of now. The effects: While you may not completely stop thinking anxiously, I find the amount of time spent worrying is greatly reduced. Usually as soon as an anxious thought crosses my mind, it's dropped within 10 seconds, and that's that. Obviously this can have a major effect, especially if you tend to overthink things. Your mind is calmer, depending on how calm or otherwise you were in the first place. Other people report benefits for focus and mental clarity too, and some people also report some sedation at higher doses. The risks: I have had no side effects while using this, and I'm pretty sure many others can say the same. Suntheanine is infamous for being safe at high doses. I have taken up to 600mg (four capsules) at once and 1050mg (seven capsules) a day without any negative effects I can definitely attribute to the suntheanine. That's not to say there definitely isn't any, but you're pretty safe with this one. The dose: The bottle suggests 1 capsule (150 mg) a day away from food. And for a lot of people, that would probably be okay. However, you are not strictly limited to this, and people with anxiety disorders can derive a lot more benefit from taking more than one. I have been told that I could take up to 1200mg a day (eight capsules) if I need to, and that larger doses in some people induces some degree of sedation (and even if it doesn't, the stress relief is still a good thing to have right before bed). I typically take one in the morning, one in the afternoon, and one or more just before I go to bed (I also take one in the middle of the night if I can't go to sleep, and I find it tends to relieve symptoms of not sleeping, which in my case, are worse and probably more anxiety-based). Lately I've been taking 600mg (four capsules) at night in response to insomnia - I can't yet conclude that this helps more since I've only done it three times. But in the beginning, one capsule was a fantastic way to end the day - it felt like all the stress of the day just vanished. The drawback of having 1200mg a day is... you'll run out of this in less than two weeks. So I prefer to keep my consumption as low as possible without ignoring this in times of high stress. My average use for right now still cleans out a bottle within 1 month (it IS important to note, however, that I am currently attempting to drop other anxiety meds, so of course I am subject to some extra stress during this time, and the fact that I use this a lot definitely does not mean that you'll have to as well). Another big plus over anxiety medication is you can simply take this as needed, not at set times every day. No withdrawal, no addiction, nothing like that. My psychiatrist has told me, however, that there are long-term benefits to using this. I haven't been able to verify that (actually, she's the only person I've heard that from, I've never read that online), but if you want to attempt to benefit from that, taking at least one a day as instructed is recommended. In general, I am very pleased with this safe and generally effective alternative to potentially risky prescription medications, and hopefully soon this is the only thing I'll be taking for anxiety.

This works really great for anxiety, calms me right down when I need it. I don't use it often but it sure is good to have it when I need it. It also helps me after a particularly long hard day at work when I'm having a lot of pain because it just relaxes me. I'm very glad it's not a prescription item. Thank you for having it Amazon!

L-Theanine was first recommended to us by a psychiatrist for our younger son when he was in 4th grade and developed a tic due to stress of a teacher in a new school. It didn't do anything for the tic, but our older son took some one day, and really felt great! He's in high school and had been feeling pretty stressed. He said it helped him feel calmer and less anxious while not losing any focus. The good thing is L-Theanine is an amino acid; it's found in green tea. It can cross the blood brain barrier and has a positive effect on alpha-brain waves; it has a relaxing effect, reducing physical and mental stress, boosts mood and cognition. It also acts in concert with caffeine to boost cognitive performance. L-Theanine has been tested on small groups of people with significant sleep disorders, and while it's not overly sedating, it does affect alpha waves and tends to be relaxing. It helps those people with sleep, as it does with anxiety. My husband and I recently added it to our Amazon subscription list of supplements when we read an article in Life Extention Foundation's December 2013 magazine about supplements one should consider adding when facing the flu. It was incredibly timely! No sooner did I get the magazine, read it, stock up and get enough for all the kids, than I got socked with a sinus infection/flu. I have never before gone without a course of antibiotics, but this time really wanted to make the effort. I hunkered down with my supplements - L-Theanine included, ate cooked mushrooms (natural anti-viral) several times, as well as maintaining good hydration, and stayed in bed. I finally made it through my very first painful sinus infection/flu w/o antibiotics! So, yes, I heartily recommend L-Theanine! I'll keep buying it for myself, my husband, and our kids!

Not bad overall but I didn't get the full effect from it

Not effective and cannot return the product either