L-theanine User Reviews & Ratings (Page 2)

• Bet...
• April 22, 2020

For Dietary Supplementation "I took this supplement this morning on the way to work. By the time I got to work, I felt a little tired and dizzy. Within an hour, I became so nauseous and dizzy, and my head felt tight, and my neck got stiff, and my arms started to feel weak, and I got a little confused when trying to talk. I had to leave and go home. I still feel all of those things. I will not be taking this supplement again."

• Rut...
• Taken for less than 1 month
• April 15, 2020

For Dietary Supplementation "This drug increased heart rate, felt sedative, and at the same time, more depressed and stressed."

• Chl...
• November 15, 2019

For Dietary Supplementation "I started taking L-Theanine about 3 months ago and I think at first I felt it helped my sleep. The last month has been horrendous. I literally would wake up 6-8 times a night wide awake. Sometimes even felt extremely anxious like a panic attack was coming on. I was wide awake all night long then exhausted the day after. Averaging 3-4 hours of restless sleep every night. I was getting extremely worried about what was happening to me. I was running low on my pills and about to order another bottle but decided to research L-theanine a little more first and saw other people having similar side effects so I immediately stopped taking them which was 3 days ago. The last 2 nights I slept so much better. No more waking up 8 times a night in a panic. I also have the MTHFR gene mutation which may be the reason why it has the opposite effect on me. L-theanine increases GABA levels which has opposite effect on those of us with the MTHFR gene mutation. My bottle is going in the trash!"

• Hal...
• Taken for less than 1 month
• September 14, 2019

For Dietary Supplementation "I was very stressed in the last weeks, so I thought that it’s time to try this out. (I am eating healthy, working out every 2nd day.) I took 100 mg last night and slept very well. The next dose today morning then... mmm... I felt so strange... I couldn’t think clearly, I felt dizzy. I was at the store and suddenly I felt that I would lose my balance... I felt that my heart would explode. Personally, I don’t recommend it."

• kat...
• Taken for less than 1 month
• July 30, 2019

For Dietary Supplementation "I struggle with Generalized Anxiety Disorder, and I hate the way medicines make me feel! I saw some stuff about l-theanine and was excited to try something holistic with so many great reviews. At first, it was great; I noticed a calming effect within 30 minutes, I felt focused and alert, and overall in a good mood. I started taking 2 100 mg pills a day. After 2-3 weeks, I started noticing some changes. I felt like I just couldn’t focus at all, was in a weird depressed mood, wanted to sleep all the time, had no motivation to go workout. And if I didn’t take it at all, I felt HORRIBLE: dizzy, anxious, bad headaches. I stopped taking it about 3 days ago, and I’m trying to adjust. It just didn’t agree with me; maybe I should have just been taking it a few times a week rather than every day, but I think for now I’ll just steer clear."

• Hea...
• Taken for less than 1 month
• June 26, 2019

For Dietary Supplementation "Took two pills before bedtime. Woke up at 1:30 with a horrible stomach ache. I’m wide awake too. I won’t take this again."

• Fai...
• March 26, 2019

For Dietary Supplementation "I started L-Theanine taking 200 mg morning and evening. I have early dementia, it was like switching a light bulb on in my brain. It helped so much with my memory, word finding, alertness, etc. However, within a week, I started getting horrendous heartburn, really bad, and quite severe pain in my stomach, and my ribs felt like I'd been kicked in my ribcage. I couldn't touch one part of my stomach. I saw my doctor and was told I had a stomach ulcer. I've never suffered from heartburn before, and it's a really weird kind. I was prescribed omeprazole, but I didn't take it. I suspected the L-Theanine, so I stopped it, after a few days, the pain went and my stomach healed up. I started it again, and after 3 days, the pains came back. To be absolutely sure, I stopped again and restarted after the pain stopped, same again, pain returned! Horrendous, bad vivid dreams as well, every night, and headaches by day."

• Pau...
• Taken for less than 1 month
• November 15, 2018

For Dietary Supplementation "Tried l-theanine for my chronic insomnia. Just one pill taken a few hours before bed made me have crazy vivid dreams almost as soon as I fell asleep, and I was awake again after only an hour but could not get back to sleep. I already have exhausting dreams when I do sleep, but this supplement seems to massively increase them even on the small dose I took. It may work for some to keep them asleep, but it's not for me. I didn't realize it increased dreaming until I researched it the next day. Seems half of other people have the same reaction."

• Lau...
• Taken for less than 1 month
• April 14, 2018

For Dietary Supplementation "After four days of taking L-Theanine - drinking matcha tea lattes 1-2 a day - I had a seizure. I noticed I felt kind of unusual after drinking the matcha tea, calm but also kind of amped up at the same time. I didn’t sleep well, and after a night where I hardly slept (had a matcha latte at 5 pm), the next morning I had a series of absence seizures. I am fairly sure it was from the L-Theanine because I have since researched it and learned that it decreases the threshold for certain types of seizures and increases the threshold for other types. I should have discontinued it when I noticed its effect on my sleep and nervous system."

• Mic...
• November 3, 2017

For Dietary Supplementation "I took L-theanine, and it made me a little relaxed, but it gave me heart palpitations. It didn't agree with me. I stopped it."

• K F...
• June 21, 2017

For Dietary Supplementation "I already drank green tea and did not realize this was in my other multivitamin supplement. This made me so dizzy after a few days I could not drive or barely think straight. It also caused extreme fatigue for me. I am only 46 and in good health/fit. I would have crashed a car if I had driven in the last 24 hours. Please be careful with this."

• zak...
• November 10, 2013

For Dietary Supplementation "I found l-theanine to have no effect on anxiety, sleep, or mood. There were no negative effects either. I used 200 mg/day."

• Oli...
• Taken for 1 to 6 months
• May 24, 2022

For Dietary Supplementation "I appreciate this does work for some people, and I agree it does relax you... until it wears off! For me, it gave me heart flutters and the worst anxiety ever once it wore off. I just didn't feel like myself and felt like I had a very low mood. Would not recommend, but I appreciate everybody's body chemistry is different. I'll stick to meditation and herbal teas."

• Anonymous
• January 29, 2022

For Dietary Supplementation "I experienced dizziness, faster heartbeats, and heightened anxiety when trying to sleep."

• cma...
• Taken for less than 1 month
• December 20, 2021

For Dietary Supplementation "If you have low blood pressure, do not take L-theanine. I took only a single capsule and have felt lightheaded and shaky to the point that my body is trembling. I feel like I am going to pass out. I was prescribed L-theanine for my general anxiety. You would think that considering I have a history of low blood pressure, the doctor would mention it could lower my blood pressure further. I guess it is on me for not doing enough research."

• swi...
• Taken for less than 1 month
• August 2, 2021

For Dietary Supplementation "I felt so spaced out, couldn't really work. I got focused on doing all kinds of things I've wanted to do for a long time, but not work. I couldn't calm down in the evening, had this urge to get stuff done, organize things, etc., very unpleasant. Somehow made me a little bit calm, but mostly way too over the place to get anything done sensibly. Now I feel exhausted after a few days of it, feel as if I'd have been on drugs for a few days."

• joe...
• Taken for 1 to 6 months
• January 24, 2021

For Dietary Supplementation "I've tried using L-theanine 2 separate times (about a week each time) to help fall and stay asleep. Although it was effective in calming you down, I felt it made my mind too alert to fall asleep, and when I did, I'd only get very light Stage 1 sleep for a couple of hours, then be up for a while around 2:00 a.m. I would recommend it for daytime use but not for sleep."

• Maa...
• Taken for less than 1 month
• November 7, 2020

For Dietary Supplementation "After two days of taking 200 mg once a day, I felt dizziness, and my body relaxed overall."

• Baz...
• Taken for less than 1 month
• August 17, 2020

For Dietary Supplementation "I read this supplement could help with withdrawals from fluoxetine, so I took a 400 mg dose (the only dosage I could find) with magnesium before going to bed. I slept very poorly that night (could have been unrelated, though). But the next day in the morning, I experienced a feeling of panic and rapid heartbeat that completely freaked me out. I was driving and thought I was going to black out. I don't get panic attacks or severe anxiety, so I decided to stop this supplement immediately. I would recommend starting on a very low dose if you are going to try this."

• Car...
• Taken for less than 1 month
• April 29, 2020

For Dietary Supplementation "I started theanine last week. It seemed great the first few days. Then, these past 2 days, it has triggered some really nasty anxiety attacks. I was up until 3 a.m. afraid to go to sleep for 2 nights in a row. It causes extreme thirst and hard and heavy heartbeats. I believe this drops my blood pressure too low in conjunction with propranolol. Will not take again. Be careful with this stuff."

• Dan...
• Taken for 1 to 6 months
• March 26, 2020

For Dietary Supplementation "I have been taking this for about a month, and only now have I started having really weird side effects. At first, it seemed to be greatly helping my anxiety, and for about a week now, I have had awful heart palpitations. I originally thought it was stress but started realizing they would start back up after I took the l-theanine. I was taking 200 mg - 400 mg a day. I also experienced low-grade nausea, especially if I did not eat, as well as dizziness and fatigue. I'm pretty sure I cannot continue this. Also, when I went to the doctor, my blood pressure was very low, and it may have been due to this. I am a 31-year-old female in very good health."

• Wen...
• Taken for less than 1 month
• February 1, 2020

For Dietary Supplementation "Initially, I really benefited from the calm feelings when I took 200 mg at bedtime. Fell asleep more easily and had relief from falling asleep anxiety. After a few weeks, however, I started getting debilitating headaches, fogginess, dizziness, and fatigue. It confined me to home. I am very disappointed."

• Res...
• Taken for less than 1 month
• December 26, 2019

For Dietary Supplementation "I took this at night to help with the inability to stay asleep and racing thoughts. I only took it a few times and not every night, more like once or twice a week. I thought it worked well the first night. Then I noticed that when I take it, I have heart palpitations. I have also been having trouble sleeping due to a burning sensation in my stomach. I realized this morning that the burning sensation and heart palpitations only happen when I take this supplement."

• Aid...
• Taken for less than 1 month
• November 6, 2019

For Dietary Supplementation "I began taking L-theanine before bed for about a week—just enough time for it to really exhibit effects—I forgot about it for 1-2 days and started again. When I started again, I experienced a large spike in anxiety compared to usual. I felt spacey, anxious, frustrated, and even violent. I am not diagnosed with any anxiety disorders but definitely experience occasional anxiety, especially in social settings and when trying to sleep. After reading a plethora of reviews, the bottom line is this: this medication is sketchy. It’s not well-studied, and the physiological mechanisms are not well outlined in literature. I’m a biochemistry major at a strong institution, so I’m not out of my element with this statement. Consult a psychiatrist before starting a dosage regimen. Hope this helps."

• Ton...
• October 27, 2019

For Dietary Supplementation "Took 200 mg a day in the morning. Had a couple of stressful weeks and wanted to try theanine after some research on the web. Tried it for 2 days, then 2 days off. Then for 5 days straight, then quit. First 2 days were okay, it reduced stress a lot. It did not increase that real focus, but it did reduce distraction and other stimuli. The effect was pretty admirable for just an off-the-shelf supplement. Also, deep sleep and pretty damn deep dreaming. During the 5-day period, I pretty much got used to and adjusted to the positive effects. Started to get bad headaches from it, my neck and jaw muscles got stiff as hell. Everything started to feel distant and off. It is way too easy to sort of 'zone out' on this stuff. Would not recommend it. Non-polarized reviews and mentions of side effects require some online digging to find."