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L-theanine for Dietary Supplementation User Reviews (Page 4)

Reviews for L-theanine

Commonly mentioned side effects
  • Tra...
  • Taken for less than 1 month
  • March 1, 2018

"I had been taking 3 mg melatonin for sleep, but wanted to cut back as it left me feeling somewhat drugged. I found a product that contains 1.5 mg melatonin plus 100 mg l-theanine in a chewable, gummy form. It’s been working great for me for about a week. I feel this combo “lets” me sleep vs. “puts” me to sleep. However, I’m not sure if it’s the level of melatonin, the l-theanine, or the combo that works so well for me, but I’ll continue with it for a while."

8 / 10
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  • Mil...
  • November 11, 2020

"I took l-theanine at a 200 mg dose at 2 am in combination with 100 mg caffeine. I was hospitalized hours later. After the extreme weakness and dangerously low blood pressure it caused, panic attacks almost drove me crazy. It doesn't seem to work well for everyone."

1 / 10
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23 Report
  • Nat...
  • Taken for less than 1 month
  • August 13, 2018

"Took this as I was suffering from anxiety and wanted to avoid prescription medication. I took this before bed, felt a little relaxed, and slept well for 3 hours. Woke up after that and could never sleep after. Don't think this is right for me, so gave up."

4 / 10
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Frequently asked questions

  • NYg...
  • Taken for less than 1 month
  • August 26, 2018

"The first time I took 100 mg of L-Theanine, it made me feel spacey, tired, and gave me a headache. It did calm me down, I felt my dopamine level rise, but the overall feeling was somewhat uncomfortable. A lot of sources recommend having coffee with it. I loved the combination. It made me feel happy, motivated, and energetic, but that didn’t last long. In 5 hours, I started to have a bad crash. I had jitters all over my body, and my heart rate was very high. I took 50 mg of L-Theanine to calm down, but it didn’t feel the same the second time, not the same mood, and I felt cranky, but it relaxed me. Since I don’t feel right after a calm down, I take 5-HTP after. I also pair L-Theanine with 5-HTP for sleep and have happy dreams, sleep, and wake up with a smile. I recommend that combination for people who suffer from depression. For those who suffer from anxiety, don’t have it with coffee and be careful with it, calm downs can be pleasant. Could be the brand too, get a quality brand."

7 / 10
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  • Tha...
  • Taken for less than 1 month
  • April 26, 2021

"I tried supplementing with L-Theanine for stress and noticed that I was getting random heart palpitations. When I stopped supplementing, they went away. It also hides in a lot of supplements. A friend's husband had the same issue from a natural sleep product that had L-Theanine in it."

1 / 10
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15 Report

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

"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."

2 / 10
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  • Egg...
  • Taken for less than 1 month
  • October 2, 2018

"I began taking this about 3 weeks ago, as it had a lot of good reviews and seemed to be helpful for those with anxiety and social anxiety, which I have both of quite badly. I take 200 mg daily, a few times I have doubled it, and only one day did I feel slightly less anxious, and by slightly less, I mean barely any difference. I have not had any good results, it's like I'm not taking anything unless it's too soon to tell."

2 / 10
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  • ONe...
  • April 25, 2023

"I have been trying for months to find a solution for my ADHD/anxiety. My therapist recommended exercise, meditation, journaling, and eating healthy (an existing habit). After months of no improvements, we were thinking of trying rx medications, which is a fear of mine because of the side effects. Before seeing a psychiatrist, I did my own research and discovered L-theanine from a YouTuber’s video that sparked my interest. I went out the next day and bought L-theanine along with a few other supplements that were recommended, and I must say, the next day I felt completely fine, with no crippling anxiety, no overthinking, and I was more outgoing. I’m looking forward to more days like this. I hope L-theanine can help you as well!"

9 / 10
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  • RJA...
  • Taken for less than 1 month
  • October 26, 2021

"I discovered L-theanine by accident through drinking green tea, which I noticed had a hugely positive effect on my mental state - feeling relaxed, calm, as well as alert with mental clarity. This led me to buy L-theanine supplements, and unfortunately, dosages from 40 mg to 400 mg each caused me physical and mental discomfort - headache, nausea, anxiety, and lack of focus. I wondered if I am sensitive to the L-theanine and should try out micro dosages."

1 / 10
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  • Maz...
  • September 2, 2020

"So I suffer from BPD and every type of anxiety, I guess. I found l-theanine and bought 450 mg ones. Took 2 pills before sleeping. Within 30 minutes, was knocked out without the daily suicidal thoughts. Everything was going so well. However, a month later, I was perfectly fine until I had a stomach ache. I went to the toilet a number of times and nothing was coming out. The following night, I had diarrhea. The worst ever experienced in my life! It was 2:30 a.m. and my stomach didn't let me sleep, so I went to the toilet. Story short, ended up unconscious in the hallway. Once I gained consciousness, I ran to the toilet again for the other half of rapid fire. It took all my energy. Today, after 2 months, again, was laughing with Mum until I had the worst stomach ache out of nowhere. I felt my body shutting down on me. I rushed to the toilet with the same signs and rapid fire before falling unconscious. Now I know it is l-theanine, I will not try these again. Please do not try this."

1 / 10
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  • Baz...
  • Taken for less than 1 month
  • August 17, 2020

"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."

2 / 10
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  • Anonymous
  • August 6, 2021

"100 to 200 mg 3 times a day helps me with generalized anxiety disorder. I also have powdered form. 1/8 tsp under my tongue relaxes my brain. Lowers cortisol at night for better sleep. Tapering off gabapentin with l-theanine and melatonin before bed. God bless, keep looking forward."

9 / 10
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  • Ter...
  • Taken for 1 to 6 months
  • December 12, 2023

"I have been taking l-theanine for almost a year now with stops, of course. The longest I have taken it was about 2-3 months, every day 400mg in the morning and 200mg at lunch (if needed). I started at a lower dose but moved up quickly. It has helped me a lot. I have C-PTSD, generalized anxiety, ADHD, autism spectrum, and depression. I also suffer from PMDD. It doesn't work for every panic-anxiety-PTSD episode I get, but sometimes even diazepam doesn't help. Most of those episodes get better in half an hour, I regain the ability to think clearly again, though I still experience intense emotions. However, they stop controlling me. It doesn't help me with sleep though, I actually get quite active. I can honestly say that l-theanine is saving me from addiction to benzodiazepines. Now I only take diazepam about 2 out of 10 times I have breakdowns. It doesn't give me brain fog, it actually lowers my heart rate (I have 90BPM almost constantly). The only issue I have with it is that it only works for 4 hours."

10 / 10
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  • Syl...
  • Taken for less than 1 month
  • December 26, 2024

"I started taking L-Theanine for sleep. It worked well, associated with magnesium glycinate and chelate. I could sleep very well, but I started to be depressed and very anxious as soon as I woke up and during the day. I am normally a very happy and active person. So I had to stop taking it, and I went back to my happy mood."

5 / 10
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  • Lau...
  • Taken for less than 1 month
  • April 14, 2018

"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."

1 / 10
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  • Lon...
  • Taken for less than 1 month
  • September 6, 2021

"I took one 200 mg pill of l-theanine to help me get rid of anxiety about one hour before I wanted to go to sleep. It elevated my anxiety with horrifying nightmares. In these nightmares, people looked like hideous mutants. I woke up several times, or I think that I did, and the horror was still playing. The nightmare came to life. That was an experience that I never want to relive! Ashwagandha works far better for me."

1 / 10
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  • joe...
  • Taken for 1 to 6 months
  • January 24, 2021

"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."

2 / 10
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  • Lyn...
  • Taken for 1 to 6 months
  • August 22, 2023

"I can't remember if I posted about this before so apologies. I've been taking 350mg once a day. I split the second 200mg powdered capsule in half. I'm trying to self-wean off my benzos as I've developed resistance and they're not effective anymore. Do not mix the two! I feel calmer and more sedated. I do get quite groggy, but I'm calm and everything just melts away without any side effects. I can handle things better. The only thing I'm worried about is my racing heart, developing resistance to it, and the vivid dreams. I'll give it more time to see if my anxiety (like racing thoughts, panic attacks and thoughtless rambling) and PMDD symptoms continue to improve. Last cycle was milder and it surprised me. I refuse to go on hormones or try another SSRI. I threw that trash Paxil in the garbage. L-Theanine seems to be working out. My cortisol hormone levels were high and I just got my blood tested last week. I was told they lowered. I'm so happy to hear that."

8 / 10
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  • Dra...
  • Taken for 2 to 5 years
  • July 23, 2021

"My neighbor (82 y.o.) was suffering from convulsions. She was taking plenty of antiepileptics to stop it, and in vain, and she was feeling like a 'vegetable.' Convulsions started suddenly and in the morning. Eventually, I put her on L-Taurine 1000 mg + L-Theanine 500 mg + L-Glycine 1000 mg along with PQQ 20 mg and Q10 - 100 mg, and her attacks stopped. She does not take her 'classic' meds anymore. Though she continues on her cardiac meds, the pleasant bonus of this cocktail was that her blocked arteries were cleared, which is amazing. Nobody expected this effect. She had both carotid arteries blocked at 75%, and when she went for a routine control, they were just 45% and 50%. The cardiologist was shocked. So she continues to take this cocktail already for 3 years, and her cognition and vision are significantly improved too. Highly recommend."

10 / 10
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  • RJA...
  • Taken for 1 to 6 months
  • February 2, 2022

"Micro dosages. Hi - I posted last year explaining how well I felt after drinking green tea. However, 40 mg-200 mg of the supplement made me feel very uncomfortable (mentally and physically). I also mentioned giving microdosing a go. I have been taking tiny amounts of the supplement in powder form at night and in the morning for 2 months, and it has done me wonders."

10 / 10
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  • Mic...
  • Taken for less than 1 month
  • June 30, 2022

"After reading the reviews, I ordered a bottle of 200 mg l-theanine capsules for anxiety, and I just took one early this morning. I didn't read anything about it needing time to take effect, but it's been about 5 hours now, and I don't feel less anxiety at all. I also don't feel productive or clarity of mind, I feel my usual burnout and chaotic mind. I just have this weird feeling in my head like the beginning of what might later be a headache, so I took some ibuprofen to avoid that. I took this capsule specifically today because I'm having irritability and a hard time functioning and getting things done. I guess if you didn't have a bunch of demanding and inconsolable children you're caring for, then this may feel like it works. Has anyone tested this with kids screaming and yelling in the background and constantly asking for things and being dissatisfied? I doubt it. I'm also having back pain from tensing up, but that might just be my anxiety."

1 / 10
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  • Jac...
  • Taken for 1 to 6 months
  • October 15, 2021

"Heart palpitations within 5 minutes of taking 100 mg. This is after about one month of usage without any problems. It was providing me the benefit of a clear head, no fogginess when waking up, but the palpitations are concerning and affect sleep quality. Will try to reduce the dosage to 50 mg."

5 / 10
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  • MrT...
  • Taken for less than 1 month
  • August 22, 2021

"I was very skeptical of a supplement doing anything for my anxiety/panic, which has been pretty strong, like a nervous breakdown. I wanted to avoid SSRIs (bad experience in the past), and therapy hadn't helped. Well, I'm shocked at how powerful L-Theanine has been. I've been taking a big dose (350 mg tablet x3 a day), and it feels like I'm taking diazepam, just without side effects or withdrawals. A zen-like blanket of the mind. The worry thoughts are still there, but it's like you float through them. Hard to describe... a warm fuzzy feeling a bit like a tab of acid (from my younger days). If you're a cynic like me, try it, definitely before your doctor puts you on a hard drug."

10 / 10
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  • Guy...
  • Taken for 1 to 2 years
  • November 5, 2022

"Most effective supplement I have ever tried. Sublingual dose works in minutes. The anxiety just kind of melts away. Works great with panic disorder and OCD. I take a half dose twice a day, but see what works for you. 10 out of 10."

10 / 10
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  • She...
  • Taken for less than 1 month
  • January 12, 2022

"I took 200 mg about a month ago for a few days to help with anxiety. It seemed to work at first, but then I felt more anxious as it wore off later. I also had a burning feeling in my stomach and reflux. The second day I took it with caffeine/coffee. I was very focused-like a robot, getting things done. The burning continued, even after taking my reflux meds. I again felt anxious when it wore off. Recently, I just took some melatonin and didn’t realize it had 200 mg of l-theanine. I later had cramping and diarrhea. That is not normal at all for me. I also woke up in the night feeling very anxious. I think it’s all from the l-theanine. I would not have taken it recently if I’d known it was in the melatonin. Magnesium works much better for me for calm and sleep, but you have to use the glycinate kind or it can cause gastro issues. I think it could help some people, but the side effects were terrible for me. In fact, it caused anxiety instead of helping it."

3 / 10
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Reviews may be edited to correct grammar/spelling or remove inappropriate content. Reviews appearing to come from parties with a vested interest are not published. This information is not intended to endorse any medication and should not replace the expertise and judgment of healthcare professionals.

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