L-theanine User Reviews & Ratings

• lis...
• Taken for less than 1 month
• March 7, 2021

For Dietary Supplementation "I got horrible chest pain and tachycardia (fast heart beats) and palpitations from just 50 mg every time I took it. I haven’t found any warnings of these side effects for this until I came on here. This site is so helpful. Be very careful with this supplement. Start very low and look out for worsening mood and anxiety. I can’t believe no other websites list these common side effects."

• jas...
• Taken for less than 1 month
• November 13, 2019

For Dietary Supplementation "I was looking for something that would help calm my brain down so I could stop overthinking about things, all in all without prescription drugs. I stumbled across L-Theanine in Walmart, so I decided to give it a try. As soon as I took it, about an hour later, I felt like I had my peace of mind back. I wasn't stressed or anxious, and it gave me my motivation back. I don't think it was a placebo effect because I haven't felt this way in a long time. I noticed in a lot of reports that people take it for sleep, but I feel it has the opposite effect on me. I feel like it gives me energy and motivation to get things done. I take about 200mg at a time, about twice a day. In a way, it kind of gives me a euphoric feeling, but not the type that is induced by prescription drugs. It's hard to explain, but it's more like a clear, peaceful, dreamy, motivational state. L-Theanine is a miracle supplement as it helps out with a bunch of my mental/anxiety issues all at once."

• Lrm...
• Taken for 1 to 6 months
• January 25, 2021

For Dietary Supplementation "Using L-theanine is my final step in curing myself from the terrible side effects of benzodiazepines. I worked long and hard to get off of 15 years of using benzodiazepines when I became intolerant 4 years ago. I now use L-theanine 200 mg four to five times per day, and life is good."

• 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!"

• Rob...
• Taken for less than 1 month
• January 12, 2014

For Dietary Supplementation "I am a 53-year-old female and have ADD. For almost 1 year, I was having extremely difficult memory problems. There weren't enough Post-it notes in the world to help relieve my anxiety about my progressing memory problem. The biggest result I have had is the ability to focus on my work, assimilate information, and stay on task. I've taken prescribed medications (Ritalin, Xanax) in an effort to correct my mild ADD. This supplement is a life-saver and job-saver for me."

• Tan...
• Taken for 1 to 6 months
• December 18, 2019

For Dietary Supplementation "L-theanine is awesome stuff that I've used for ADHD/anxiety for a while. I'm off all ADHD and anxiety meds. Let me correct a few things I've seen in other reviews: #1 it is NOT a drug. L-theanine is simply an amino acid. #2 it does react strongly with coffee and caffeine. Just be aware. #3 figure out your dose. It is not a prescription medication. Often it's suggested to take 100 mg twice a day. That is just a suggestion. I had side effects so I just lowered the dose. I adjusted down because of my metabolism. I only take 50 mg a day. I'm 6 foot tall and over 200 lbs. I get the chewable tablets so I can break them in half. Works like a charm."

• Nat...
• Taken for less than 1 month
• September 28, 2016

For Dietary Supplementation "I have PTSD, generalized anxiety, and panic disorder from years of substance abuse which affect many facets of my health. I cannot handle stress well, my head is usually pulsing or aching, and I frequently get dizzy spells and feel lightheaded. I tried Lexapro, and it did not really make me feel well. It helped with anxiety and the panic attacks, but I felt emotionally flat and withdrawn from life. Since stopping the Lexapro, I have resumed many of my previous daily symptoms associated with anxiety. I just started taking a liquid concentrate of L-theanine sublingually, and it is nothing short of a miracle. My head is clear again, and I can actually deal with my responsibilities. I feel like my life was given back to me. Highly recommended."

• Aha...
• April 3, 2017

For Dietary Supplementation "I have been having roughly 4 panic attacks daily for a month. I hate pharm. drugs, so I tried this. Worked immediately!!!!! Within 20 mins, I felt like I've never had anxiety in my life. This supplement is great!"

• Aut...
• Taken for less than 1 month
• June 25, 2016

For Dietary Supplementation "I purchased this product a few days ago because it's a safe alternative to SSRIs for my son's anxiety. He's on the autism spectrum, he's 13 with severe anxiety. I have been giving him 100 milligrams 3 times a day, and he told me how much better he feels, he's so much happier. He isn't easily distracted or buried in video games. He's talkative, and his conversations are appropriate. So far, I think this is a miracle drug. I really hope this continues."

• TTa...
• August 28, 2016

For Dietary Supplementation "I have been prescribed just about every drug (chemical) they have for anxiety and depression. After finding out about the benefits of L-Theanine, I have been taking 200mg per day, and I feel like I did before I knew depression ever existed! Amazingly, my body is reacting very well to the supplement and has not experienced a withdrawal effect from no longer taking the Xanax. I love that it's all-natural, it's like brain food. I feel so alive."

• Onl...
• Taken for 1 to 2 years
• October 17, 2020

For Dietary Supplementation "I was diagnosed with anxiety about a year and a half ago and refuse to take prescription medication due to the long-term side effects. I did hours and hours of research to find something that helped. I found L-Theanine, which is NOT a drug as some have mentioned, and have experienced nothing but relief. For those with anxiety still drinking caffeine and still having anxiety/panic, kick the caffeine out of your life!! I'd have all-day anxiety and insomnia but after taking 100mg of L-Theanine 3 times per day, I have felt much better without taking a drug. Give this a try, it's not a drug."

• Pat...
• July 23, 2017

For Dietary Supplementation "Anxiety was so bad, e.g., I'd start to peel an onion, but was frightened that I couldn't finish, so felt incapable of making the whole meal! Mental fear about everything! Note: I didn't eat healthy, nor was I motivated to exercise. I was on medication for approximately 10 years but didn't want to forever. I tried natural remedies and mind exercises, but they didn't do much for me. Then I heard of L-theanine, researched, and bought some. 1 tablet per day for 7-10+ days, before a tiny 'glimmer' of hope. Now, 2 months later, I feel okay - with an occasional bad day. I'm eating healthy now and exercising, which together can help anxiety. L-theanine got me feeling well enough to take care of myself. I really hope it can kick-start you too into getting better.♥ Pat"

• Bri...
• February 24, 2017

For Dietary Supplementation "I've always been a kind of anxious person, but after years of alcohol abuse, my anxiety hit the roof. I had anxiety for months on end and could find no relief. Eventually, I had to start working out three times a day to actually get relief from anxiety. After days and days of researching, I finally stumbled upon green tea and how it can relax you. I started drinking gallons of green tea every day and started feeling a little bit less anxious. After a few weeks of doing this, I decided to look into why green tea helped and found out it was L-theanine. I took these pills three times a day for three months and was finally able to breathe again. Greatest discovery ever!!! I highly recommend trying them."

• Diz...
• July 25, 2016

For Dietary Supplementation "Military veteran suffering from PTSD, anxiety, and insomnia. I was skeptical at first, but after taking 400mg per day, I definitely notice a difference. Not a miracle happy pill, but it takes the edge away and allows me to feel halfway normal in stressful situations. It helps take my stomach out of knots and I sleep a little better. Can't complain, will continue to take."

• cla...
• Taken for 1 to 6 months
• May 14, 2021

For Dietary Supplementation "I am a 52-year-old average size (5'10', 180 lbs) male. I suffer from severe depression, anxiety with panic attacks, and agoraphobia. Medications given by my psychiatrist only stabilize me to be functional. THEN I found L-Theanine. When my anxiety begins rising toward a panic attack (throwing my mood deeper into depression), I take 200mg of L-Theanine. Within 45 minutes, I just notice 'hey, no panic attack yet' and 'I feel so calm.' If I still feel a bit anxious after 45 minutes, I take another 200mg. I take 200mg before I leave my home. It doesn't make me tired but does give me a relaxed sleep. The only side effects I have noticed are sometimes a slight headache and moderate nausea if I take on an empty stomach. I prefer it over Rx meds to avoid the dizziness and chance of addiction. L-Theanine has dramatically improved my quality of life. It is my lifesaver!"

• Kiw...
• Taken for 2 to 5 years
• September 6, 2015

For Dietary Supplementation "I take about 800 mg of L-theanine approx 1/2 hour before skating competitions to reduce my stage fright/performance anxiety. I have also taken it before presentations at work. It works amazingly well at eliminating my anxiety and allowing me to focus so that I can utilize all my practice and preparation (without being hindered by anxiety). The other benefit of L-theanine is that it doesn't make me drowsy. My Naturopath first prescribed it, and now I just buy it."

• Goa...
• Taken for 1 to 6 months
• January 29, 2019

For Dietary Supplementation "Have been taking Xanax for sudden anxiety attacks for years but decided to try L-Theanine and have had very good results. I take 200 mg 3x a day and am impressed with how well it works. Just to feel a calmness and helps me think clearly. I can focus and it stops the shaky hands and panic breathing. Also getting much better sleep, was waking up every 2 hours with feeling of 'dread', no more. It did take about a week of regular dosing to find my appropriate dose and get steady effect. I am glad I found it."

• 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."

• Ted...
• Taken for 6 months to 1 year
• September 24, 2018

For Dietary Supplementation "I am an adult male with generalized anxiety disorder. I have taken benzos and antidepressants, but the side effects were not worth it. L-Theanine, while mild, is effective in reducing my anxiety and stress enough for me to not feel miserable every day, and it also helps me sleep. I have never experienced a negative side effect from it, and I have been taking it almost daily for several months."

• Jin...
• April 1, 2019

For Dietary Supplementation "I have had to rely on Xanax for the past 25 years, plus a beta blocker to fall asleep and stay asleep due to most likely an inherited genetic condition. However, in the past few weeks, I’ve started taking L-theanine (100mg capsules) in the evenings after dinner to see if I could lower the intake of Xanax and/or not experience wakefulness in the very early morning hours (between 3 am - 5 am). I started at the recommended dose of 100-200 mg and by the fourth day, I took 600 mg - on the day that I took the 600 mg after dinner and before I take my beta blocker, I noticed a difference in my relaxation. Furthermore, I am taking 25% less Xanax. I slept very soundly through the night - also backed up by my smartwatch sleep monitor - which indicated a 4.5-5.0 on the sleep quality scale (5-point scale). I will continue to take the 600mg after dinner to help with my sleep disorder. I would love to be off benzodiazepines or at least lowering my dose by 50-75%."

• lif...
• Taken for less than 1 month
• September 24, 2020

For Dietary Supplementation "I write this as I was searching for adverse effects from l-theanine. Well, lo and behold, I see others on there have also experienced dizziness and strange symptoms. I currently take 1 mg of Klonopin and 50 mg of Zoloft daily. I decided to try 200 mg of l-theanine last night. My hands are still shaky as I type this almost 24 hours later. I was unable to leave my house today due to dizziness, exhaustion, depression, and anxiety. When I woke up last night to go to the bathroom, I felt like the room was spinning, and I awoke from a coma. I can only conclude that the l-theanine reduced my blood pressure to near zero. There were no indications that I could not take it with the medications I am on. Well, guess what? IT HAD A VERY BAD ONE! Those of you on medications, be very cautious!"

• Anonymous
• Taken for less than 1 month
• May 19, 2017

For Dietary Supplementation "Been recently suffering from anxiety attacks and don't want to use prescription meds so tried this out since it states no drowsiness! I've been taking it for 2 weeks now, in the morning when I wake up and in the evening before bed. It has been great in calming me down and decreasing my shortness of breath! It takes about 15-20 minutes for it to start working for me. I will be taking this as a supplement from now on since it helps me to be alert and focused."

• 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."

• 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."

• 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."