Can L-Theanine Help with Anxiety?

Author’s Note: I fully recognize that I’m not a doctor, & certainly, before starting any new supplement regime ~ consult your doctor. However, this article, “Can L-Theanine Help with Anxiety?” is meant to serve as a bridge: offering a potential solution that is highly effective in terms of calming & reducing stress in the nervous system.

I read a NY Times article the other day that has stuck with me since, detailing the beginnings of a mental health epidemic ~ particularly among adolescents.  Pediatricians across the country are being swamped by teens in crisis, who are unable to get into psychiatrists, often for months at a time.  So pediatricians stand on the front lines, dealing with crises they’re only partially equipped to deal with: passing out prescriptions after 15-minute consultations.  I think this is the part that really got to me: are prescription medications for teens after cursory examinations really the best way to go, particularly for ailments like anxiety? 

Can L-Theanine Help with Anxiety? Girl Who Travels the World

L-theanine helps you feel like this: calm, relaxed ~ yet alert & present. It’s quite a powerful combination…

Enter: L-theanine.

What if we could try something else first, that was non-addictive ~ yet still highly effective at reducing anxiety & increasing focus?  In this article, I’ve rounded up a bunch of studies that show the efficacy of one particular amino acid, which I’m sure many have never heard of: L-theanine.  I’d never heard of it either until I started listening to podcasts by highly-renowned Stanford Neuroscientist Andrew Huberman (if you’ve never heard of him, trust me: you will soon): L-theanine is one of his top recommendations for relaxation, focus, & sleep.  For sleep in particular, he rates it higher in efficacy even than melatonin.

If I had to some up the effects of L-theanine for me personally, I would say: it calms my nervous system. You can actually feel it; the effects are palpable. This does not necessarily mean it puts me to sleep ~ if I take it during the day, it helps me focus. If I take it at night, it helps ease me into a very relaxed state.

What is L-Theanine?

First off, what is L-theanine?  It’s an amino acid typically found in green & black teas, as well as some mushrooms; it eases the mind without causing drowsiness (which makes it different from melatonin, for instance).  L-theanine is specifically related to reducing levels of stress & anxiety, both in the general population ~ & also for those with anxiety disorders & schizophrenia, per this study published in the Journal of Clinical Psychiatry.  The study found that L-theanine “possesses neuroprotective, mood-enhancing, & relaxation properties.”

We’ll get into more studies below, but it should also be noted that, at this time, there are no known side effects of consuming L-theanine.  This doesn’t mean that it won’t interact with existing medications ~ so please: consult your doctor before trying.  But I do believe its overall strong safety profile is why doctors like Andrew Huberman, who have very large audiences, feel comfortable recommending it to the majority of their listeners.

Can L-Theanine Help with Anxiety? Girl Who Travels the World

L-theanine is an amino acid found only in a few substances: green tea being one of them.

70% of counties across the U.S. “lack a psychiatrist specializing in children or adolescents.” One doctor profiled in the article, Dr. Dennison, based out of Kentucky, said that 20 years ago, only about 1% of her cases related to mental health.


Now, at least 50% do.


– From the New York Times piece, “Teens in Distress are Swamping Pediatricians

What is Causing this Crisis with Teens?

The author of the NY Times article, Matt Richtel, spent over one year interviewing doctors, adolescents & their families, in order to get a better handle on the mental health crisis: & he is quick to point out, it can’t really be attributed to one particular cause.  More time on screens (which really up-ticked around 2009) has led to declines in sleep & reduced physical activity amongst adolescents.  He stresses that the sleep component, particularly for teens, is a crucial link: poor sleep is associated with almost every negative health outcome.  And this is where supplements such as L-theanine may help play a critical role: in their ability to promote a calm & relaxed state, particularly before bedtime. 

Because as many of the teens (& adults I know) state, it can be hard “to turn their minds off” at the end of the day.

“Some health experts have expressed alarm that, nationwide, major psychiatric drugs are so widely prescribed to children & adolescents even though many of these medications have not been studied for their combined or long-term effects. They also worry that some antidepressants have been shown to increase the risk of suicide among children & adolescents.”


– From, “Teens in Distress are Swamping Pediatricians

Benefits of Taking L-Theanine

  • Better mental focus (particularly when taken in conjunction with caffeine ~ see studies below);
  • Increased cognition & performance;
  • L-theanine may affect levels of certain chemicals in the brain, such as: the “feel-good” hormones of serotonin & dopamine, & cortisol (aka “the stress hormone”);
  • Better sleep;
  • Andrew Huberman also cites that L-theanine helps the body get into REM sleep quicker ~ & REM sleep (“Rapid eye movement”) is critical for achieving the highest-quality sleep, more vivid dreams, & overall a more restful night’s sleep;
  • Enhanced relaxation, which in turn may lower blood pressure.
Can L-Theanine Help with Anxiety? Girl Who Travels the World

Chart courtesy of FlowBlend.

Studies on the Efficacy of L-Theanine

  • This study by Science Direct, showed that participants who were given L-theanine demonstrated “significant enhanced activity of alpha” brain waves, lowered heart rate, elevated visual attention, & improved reaction time compared to a placebo.

The importance of alpha brain waves should be mentioned here: they ease anxiety, lower depression, boost creativity, increase pain tolerance, & boost resilience to stress.  They are associated with the coveted “flow” state, or of being “in the zone.”

  • This study by the National Library of Medicine, showed that stress & depression decreased after administration of L-theanine; sleep disturbances were reduced, while cognitive function & verbal fluency increased. The study’s overall findings were that “L-theanine has the potential to promote mental health in the general population.”
  • This study, also by the National Library of Medicine, found that the combination of caffeine and L-theanine improved both speed & accuracy of performance of a specific task, & critically: “reduced susceptibility to distracting information” at both the 60 & 90-minute marks. The study concluded that the combination of L-theanine & caffeine is beneficial for “improving performance on cognitively demanding tasks.”
  • A 2018 study of people with depression & generalized anxiety disorder reported “greater sleep satisfaction” after taking L-theanine as compared to a placebo.
  • Stanford Neuroscientist Andrew Huberman includes L-theanine along with Magnesium L-Threonate in his much-talked about “Toolkit for Sleep.”  He recommends taking between 100-400 mg/day of L-theanine.  Another tool for sleep is regular sauna use (or hot baths): the heat decreases cortisol, which in turn helps the body fall asleep faster.



Magnesium L-Threonate

Can L-Theanine Help with Anxiety?

Between studies from the scientific community, anecdotal evidence, & the advice of many renowned doctors (of which Huberman is just one), I think L-theanine is potentially an exciting option for those dealing with stress & anxiety ~ or those who have children facing these issues.  And certainly one of its most exciting components is its lack of known side effects. 

If you have personally used L-theanine ~ please feel free to leave your anecdotal experience in the comments below.  Knowledge is power, particularly in the arena of mental health: I would love to hear your experience with this particular supplement.

xoxo Noelia

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What are the Benefits of Taking L-Theanine? Girl Who Travels the World

Can L-Theanine Help with Anxiety? Girl Who Travels the World