5/30/2025
Last update
5/30/2025
Reviewed By
Overview
SCIENTIFIC SCORE
Possibly Effective
Based on 2 Researches
7
USERS' SCORE
Good
Based on 24 Reviews
8.1
Supplement Facts
Serving Size: 1 Veg Capsule
Amount Per Serving
%DV
L-Theanine
100 mg
**
Decaffeinated Green Tea (Camellia sinensis) (Leaf)
250 mg
**
Top Medical Research Studies
7
We conducted a randomized, double-blind, placebo-controlled trial to see how L-theanine affects sleep quality in boys aged 8 to 12 diagnosed with ADHD. Over six weeks, participants took either L-theanine or a placebo.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
7
Exploring L-theanine and cognition in ADHD
We examined the effects of L-theanine and caffeine on cognitive functions in boys aged 8-15 with ADHD. In this study, we used a careful method to administer L-theanine, caffeine, their combination, and a placebo to the boys.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
Most Useful Reviews
9
Enhanced focus benefits
7 people found this helpful
L-theanine is a quality supplement for anxiety and stress, derived from green tea. It should be taken with food. A study published in Nature indicates that the combination of caffeine and theanine helps individuals with ADHD maintain calm focus. The capsules are odourless and tasteless. I’ve been using this remedy since 2015, and it has consistently helped. My Fitbit shows a decrease in heart rate a few hours after intake. Since L-theanine has a half-life of 90 minutes, another capsule is needed after about three hours. It's suitable for a vegetarian diet.
9
Calmed my anxiety
2 people found this helpful
L-theanine is an excellent quality supplement for anxiety and stress, made from green tea. It should be taken with food. Notably, Nature has published research showing that caffeine and L-theanine can help those with ADHD achieve a calm focus. The capsules are also odourless and tasteless. I have been using this product since 2015, and it has consistently aided me. My Fitbit indicates a reduced heart rate following consumption. Since L-theanine has a half-life of 90 minutes, I usually take another capsule after three hours. This supplement is suitable for a vegetarian diet.
9
Reduced medication side effects
1 people found this helpful
I use this to mitigate the side effects of my ADHD medication, particularly bruxism (teeth grinding). It provides a calming effect without acting as a CNS depressant or a controlled substance. I feel it has worked effectively, allowing me to tolerate my ADHD medication without the discomfort of grinding my teeth to the point of bleeding. I have tried other brands, and this one is significantly superior.
Medical Researches
SCIENTIFIC SCORE
Possibly Effective
Based on 2 Researches
7
- All Researches
7
Exploring L-theanine and cognition in ADHD
We examined the effects of L-theanine and caffeine on cognitive functions in boys aged 8-15 with ADHD. In this study, we used a careful method to administer L-theanine, caffeine, their combination, and a placebo to the boys.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
7
We conducted a randomized, double-blind, placebo-controlled trial to see how L-theanine affects sleep quality in boys aged 8 to 12 diagnosed with ADHD. Over six weeks, participants took either L-theanine or a placebo.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
User Reviews
USERS' SCORE
Good
Based on 24 Reviews
8.1
- All Reviews
- Positive Reviews
- Negative Reviews
9
Enhanced focus benefits
7 people found this helpful
L-theanine is a quality supplement for anxiety and stress, derived from green tea. It should be taken with food. A study published in Nature indicates that the combination of caffeine and theanine helps individuals with ADHD maintain calm focus. The capsules are odourless and tasteless. I’ve been using this remedy since 2015, and it has consistently helped. My Fitbit shows a decrease in heart rate a few hours after intake. Since L-theanine has a half-life of 90 minutes, another capsule is needed after about three hours. It's suitable for a vegetarian diet.
9
Calmed my anxiety
2 people found this helpful
L-theanine is an excellent quality supplement for anxiety and stress, made from green tea. It should be taken with food. Notably, Nature has published research showing that caffeine and L-theanine can help those with ADHD achieve a calm focus. The capsules are also odourless and tasteless. I have been using this product since 2015, and it has consistently aided me. My Fitbit indicates a reduced heart rate following consumption. Since L-theanine has a half-life of 90 minutes, I usually take another capsule after three hours. This supplement is suitable for a vegetarian diet.
9
Reduced medication side effects
1 people found this helpful
I use this to mitigate the side effects of my ADHD medication, particularly bruxism (teeth grinding). It provides a calming effect without acting as a CNS depressant or a controlled substance. I feel it has worked effectively, allowing me to tolerate my ADHD medication without the discomfort of grinding my teeth to the point of bleeding. I have tried other brands, and this one is significantly superior.
10
Lifesaver for concentration
I have ADHD, and this supplement is a real lifesaver for me. Theanine makes it easier to concentrate and soothes effectively without causing drowsiness.
9
Visible difference noted
This product has produced great results for ADHD, and I can truly see the difference. It’s essential to have this supplement in every household.
Frequently Asked Questions
7.5
Improved concentration
During a stressful week, I tried L-theanine in combination with caffeine. I felt the effects immediately. This combination significantly aids my concentration despite my ADHD diagnosis (as indicated by Google). It helps me read without distractions. Thanks to theanine, the caffeine influences my brain rather than my physical activity. However, after stopping caffeine, my stress resistance decreased slightly. I've increased my intake from two to three tablets in combination with caffeine, and I recommend this supplement to others, especially when paired with caffeine.
9
Visible results
An excellent product bought for my 10-year-old with ADHD. In conjunction with magnesium, the effects became noticeable after a week. He takes 100-200 mg daily, along with an additional 25 mg before bedtime in another preparation.
6
Eased daily stress
1 people found this helpful
Juggling work and caring for children with ADHD leaves me feeling tense daily, making sleep difficult. After a few days of taking this supplement, I noticed some improvement, and I will continue using it.
10
Lifesaver for concentration
I have ADHD, and this supplement is a real lifesaver for me. Theanine makes it easier to concentrate and soothes effectively without causing drowsiness.
9
Reduced medication side effects
1 people found this helpful
I use this to mitigate the side effects of my ADHD medication, particularly bruxism (teeth grinding). It provides a calming effect without acting as a CNS depressant or a controlled substance. I feel it has worked effectively, allowing me to tolerate my ADHD medication without the discomfort of grinding my teeth to the point of bleeding. I have tried other brands, and this one is significantly superior.
7.5
Improved calmness
5 people found this helpful
I am taking L-theanine for my son, who exhibits characteristics of ASD and ADHD. As I can't take the capsules yet, I open them and mix the contents with yogurt, though I can also drink it straight. I’m not certain if it’s solely due to this, but I can now remain calm when it’s time to make transitions, avoiding the tantrums and self-harm I experienced previously. After over a year of usage, I no longer face those issues. While I can’t be sure it's the only factor, there are no side effects, and I intend to keep taking it as I struggle with concentration due to my ADHD. I appreciate the good value of Caligo's products, and I'm pleased to incorporate this one as well.
7
Exploring L-theanine and cognition in ADHD
We examined the effects of L-theanine and caffeine on cognitive functions in boys aged 8-15 with ADHD. In this study, we used a careful method to administer L-theanine, caffeine, their combination, and a placebo to the boys.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
We found that L-theanine significantly improved overall cognition compared to the placebo. The combination of L-theanine and caffeine also produced positive effects on cognitive performance, revealing potential benefits for attention and inhibitory control. However, caffeine negatively affected these areas, while L-theanine showed a slight worsening trend in inhibitory control.
Overall, L-theanine combined with caffeine may be a promising option for helping children with ADHD, though more research is needed.
7
We conducted a randomized, double-blind, placebo-controlled trial to see how L-theanine affects sleep quality in boys aged 8 to 12 diagnosed with ADHD. Over six weeks, participants took either L-theanine or a placebo.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
The results showed that 400 mg of L-theanine daily significantly improved sleep quality in these children. Since many kids with ADHD struggle with sleep issues, this suggests L-theanine could be a beneficial addition to managing ADHD symptoms. Future research with larger groups is encouraged.
References
- Kahathuduwa CN, Wakefield S, West BD, Blume J, Dassanayake TL, et al. Effects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT. Sci Rep. 2020;10:13072. 10.1038/s41598-020-70037-7
- Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16:348.
