L-theanine benefits may include helping you relax, de-stress, and sleep better.
That means some supplement products may not contain what the label says.
What Is L-Theanine?
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L-theanine is an amino acid found in tea and theBay boletemushroom.
How much L-theanine is in green tea?
Anywhere from 1 to 3 g of tea have been used per cup.
This means a cup of green tea may have anywhere from around 6.5 to 19.5 mg of L-theanine.
No supplement is intended to treat, cure, or prevent disease.
Researchers have studied L-theanine’s effects for several conditions.
However, it’s important to note that better-designed clinical trials are still needed.
In an older study of young adults, L-theanine with caffeine helped with attention.
Attention issues can have the following causes and/or associations:
Addressing any underlying issues is worth considering.
If you have questions about your child’s symptoms, it’s best to contact their pediatrician.
A study was conducted in male children (8 to 15 years) with ADHD.
L-theanine improved total cognition compared to a placebo (an inactive substance).
Both L-theanine alone and an L-theanine-caffeine combination also reduced mind wandering.
Some children with ADHD may also have significant issues with sleep.
Sleep disturbances can impact both a child’s and family’s well-being.
A clinical study suggested L-theanine helped sleep quality in male children 8 to 12 years with ADHD.
Further, higher-quality studies are needed to confirm these results.
Scientists found L-theanine hasanxiolytic(anti-anxiety) effects.
While there’s promising evidence, conflicting evidence of theanines effectiveness for anxiety also exists.
Speak with your healthcare provider if you’re experiencing anxiety.
Blood Pressure
Some older studies suggest that L-theanine may help manage high blood pressure.
However, clinical trials (research in humans) are needed before recommendations can be made.
Depression
In one study, researchers added L-theanine to current medication in people withmajor depressive disorder.
The following symptoms improved:
Further, high-quality studies are needed.
Reach out to your healthcare provider if you’re experiencing depression.
Promptly diagnosing and treating this and other mental health issues is important.
Immune Effects
L-theanine impacts the immune system.
In a study of professional athletes, L-theanine affected differentimmune system markers.It was associated with decreasedinterleukin-10(IL-10).
Further study is needed.
Schizophrenia
In people withschizophreniaorschizoaffective disorder, L-theanine was added toregular treatmentwith beneficial effects.
Sleep Issues
Chronicsleep disorderscan seriously affect your quality of life.
Stress
Researchers studied theanine for itsstress-reducing effects.In young adults, L-theanine reduced stress.
An older study also reported that it loweredblood pressurein high-stress situations.
Further study is needed to confirm these results.
How It Works
Researchers believe L-theanine improves sleep quality viaanxiolysis(reducing anxiety), not sedation.
L-theanine is available in the following forms:
Theanine is also found intea.
It’s often combined with other ingredients.
Vegetarian and vegan products are available.
The following are dosages used in clinical studies.
Acupuncture has also been touted for itsanxiety-loweringandsleep-inducingeffects.
Summary
L-theanine is an amino acid found in tea and in the Bay bolete mushroom.
It is also available as a supplement.
L-theanine has been studied for use in people with conditions such as ADHD, depression, and anxiety.
It may also help improve cognition, manage stress, and improve sleep.
While results are promising, more research is needed.
2021;13(11):4059. doi:10.3390/nu13114059
The American Academy of Child and Adolescent Psychiatry.Caffeine and children.
2017;19(3):235-250. doi:10.1007/s40272-017-0224-6
Centers for Disease Control.Data and statistics on childrens mental health.
Centers for Disease Control.Early release of selected estimates based on data from the 2022 National Health Interview Survey.
2011;16(4):348-354.
2016; 8(1):53. doi: 10.3390/nu8010053.
2021;13(12):e20828.
2011;34(4):155-160. doi:10.1097/WNF.0b013e318220d8c6
National Institutes of Health.Dietary supplement label database.
2008;17 Suppl 1:167-168.
Food and Drug Administration.GRAS Notices.
