Life Extension Magazine®
Woman stretching and relaxing at desk from green tea derived L-theanine

All-Day Stress-Relief Form of L-Theanine

Clinical studies show a tea extract enables calming relaxation. A sustained-release tea formula can help manage stress all day long.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, on October 2021. Written By Caroline Miller.

A majority of people today report frequent work-related stress and other anxiety issues that can lead to burnout.

Drugs designed to reduce stress and anxiety can sedate users and have addictive side effects that preclude long-term use.1

A compound found in green tea, L-theanine, promotes relaxation and stress relief without drowsiness.2

L-theanine is rapidly metabolized in humans. Due to this rapid breakdown, multiple doses of L-theanine are needed throughout the day.3

Delivering L-theanine with a sustained-release technology helps overcome this problem, allowing its calming benefits to be spread out for stress relief.

Chronic Stress and Burnout

Brain with firing neurons under stress and in threat of burnout

Surveys and studies in recent years show that stress is extremely common in the U.S.4,5

Besides work-related stress, relationships, health, and finances can be additional sources of anxiety.4

Ongoing, chronic stress increases the risk for anxiety disorders and depression.6

Some reports found that as many as 80% of workers experience job-related stress.5

Recently, the World Health Organization (WHO) recognized the impact of chronic workplace stress on an occupation-related syndrome called burnout, and the need for evidence-based guidelines to address it.7

Burnout is marked by:7

  • Feelings of low energy or exhaustion,
  • Increased "mental distance from one’s job," or having cynical or negative feelings about work, and
  • Reduced ability to perform well at work.

A Superior Stress Reliever

Woman waking up refreshed and less stressed through L-theanine

Most medications designed to reduce stress and anxiety also sedate users or have other side effects that preclude their long-term use.1

L-theanine is an amino acid primarily found in green tea. It has long been recognized for its ability to calm the mind and produce a state of "alert relaxation."8

Its benefits are in large part due to its close resemblance to glutamate, an excitatory neurotransmitter in the brain which rises during times of stress.9

L-theanine inhibits the activity of glutamate by blocking it from binding to receptors in the brain, tamping down stress-related brain stimulation. L-theanine also stimulates production of the relaxing neurotransmitter GABA.10-13

Numerous studies have shown that L-theanine is effective at reducing stress.2,8,14,15

There has been a problem in that L-theanine is rapidly metabolized. That means, after consumption, it stays in your system for a short period of time.3

To get all-day stress relief benefits from L-theanine, people needed to take multiple doses spaced throughout the day.

Technology has solved this issue.

Using a sustained-release delivery system, a single dose of L-theanine can provide potent stress relief all day long.

Unlike anti-anxiety drugs that can compromise brain functions, studies suggest that L-theanine improves cognitive performance under stress.11,16

Reduce Stress and Fight Burnout

Woman stressed at office desk and at risk of work-stress burnout

Several clinical trials have found that L-theanine relaxes the mind without inducing sleep or sedation.2,8,14,15 In one study, pharmacy students starting high-stress clinical training were randomized to receive 200 mg of L-theanine twice per day or a placebo.17 Those taking L-theanine reported feeling significantly less stress than the placebo group.

Because burnout results from work-related stress,18 the ability of L-theanine to help prevent and reduce burnout is promising.

Physical Benefits

L-theanine doesn’t just make people feel less stressed. It has physical benefits as well.

During times of stress and anxiety, for example, the heart beats faster. Studies have shown that the heart rate response to a stressful task is reduced after consuming L-theanine,19 suggesting a reduction in stress.

Cortisol is often referred to as a "stress hormone" because its levels tend to rise with stress. Chronically elevated cortisol and other stress hormones can contribute to weight gain, heart disease, impaired memory, and other problems.6

A study measuring cortisol levels in saliva found that it wasreduced after intake of a nutrient drink containing L-theanine.20

Alpha waves are a type of brain wave that can be seen on an electroencephalogram (EEG). Their presence is associated with a relaxed but alert mental state which is necessary for focused attention.21

Studies of L-theanine have found that it increases alpha-wave activity in the brain, especially in individuals having high levels of anxiety.15,20,22,23

These results show that L-theanine not only reduces feelings of stress, but also reduces the physical signs of stress in the body. This is an important indication that this amino acid may reduce the toll that chronic stress can take on overall health.

What you need to know

Green tea leaves on plant where the amino acid L-theanine is derived from

A Safe Way to De-Stress

  • Chronic stress affects a large majority of adults. It contributes to poor general health and increased risk for anxiety and depression.
  • Most available medications to manage stress cause sedation or other side effects and may be addictive.
  • L-theanine is an amino acid found in green tea that has long been known to relax the mind and reduce stress, while maintaining alertness.
  • Regular L-theanine is rapidly metabolized in humans, requiring repeat dosing throughout the day.
  • A new sustained-release formulation provides continuous L-theanine to help manage stress and maintain productivity all day long.


Woman reading on stress-relief benefits of L-theanine on tablet

Chronic, long-standing stress affects much of the adult population.

Most stress or anxiety drugs cause sedation and other negative side effects and may be addictive.

L-theanine, an amino acid found in green tea, has long been known to induce a state of alert relaxation. It relieves stress while maintaining mental clarity and sharpness.

L-theanine is rapidly metabolized in humans, requiring repeat dosing throughout the day to manage stress.

A novel sustained-release formulation of L-theanine solves this problem, providing continuous L-theanine to help maintain an alert but relaxed mind all day long.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.


  1. Fluyau D, Revadigar N, Manobianco BE. Challenges of the pharmacological management of benzodiazepine withdrawal, dependence, and discontinuation. Ther Adv Psychopharmacol. 2018 May;8(5):147-68.
  2. Williams JL, Everett JM, D’Cunha NM, et al. The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review. Plant Foods Hum Nutr. 2020 Mar;75(1):12-23.
  3. van der Pijl PC, Chen L, Mulder TPJ. Human disposition of L-theanine in tea or aqueous solution. Journal of Functional Foods. 2010 2010/10/01/;2(4):239-44.
  4. Available at: Accessed September 8, 2021.
  5. Available at: Accessed July 7, 2021,
  6. Available at: Accessed September 8, 2021.
  7. Available at: Accessed September 8, 2021.
  8. Mason R. 200 mg of Zen: L-Theanine Boosts Alpha Waves, Promotes Alert Relaxation. Alternative and Complementary Therapies. 2001;7(2):91-5.
  9. Moghaddam B, Bolinao ML, Stein-Behrens B, et al. Glucocorticoids mediate the stress-induced extracellular accumulation of glutamate. Brain Res. 1994 Aug 29;655(1-2):251-4.
  10. Yoto A, Motoki M, Murao S, et al. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012 Oct 29;31:28.
  11. Nathan PJ, Lu K, Gray M, et al. The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother. 2006;6(2):21-30.
  12. Vuong QV, Bowyer MC, Roach PD. L-Theanine: properties, synthesis and isolation from tea. J Sci Food Agric. 2011 Aug 30;91(11):1931-9.
  13. Di X, Yan J, Zhao Y, et al. L-theanine protects the APP (Swedish mutation) transgenic SH-SY5Y cell against glutamate-induced excitotoxicity via inhibition of the NMDA receptor pathway. Neuroscience. 2010 Jul 14;168(3):778-86.
  14. Turkozu D, Sanlier N. L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety. Crit Rev Food Sci Nutr. 2017 May 24;57(8):1681-7.
  15. Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pac J Clin Nutr. 2008;17 Suppl 1:167-8.
  16. Tian X, Sun L, Gou L, et al. Protective effect of l-theanine on chronic restraint stress-induced cognitive impairments in mice. Brain Res. 2013 Mar 29;1503:24-32.
  17. Unno K, Tanida N, Ishii N, et al. Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary alpha-amylase activity, trait anxiety and subjective stress. Pharmacol Biochem Behav. 2013 Oct;111:128-35.
  18. Available at: Accessed,
  19. Campbell A, Sixtus R. The Effects Of The Alphawave® L-Theanine Study Product On Relaxation, Clarity And Cognitive Function. 2016.
  20. White DJ, de Klerk S, Woods W, et al. Anti-Stress, Behavioural and Magnetoencephalography Effects of an L-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial. Nutrients. 2016 Jan 19;8(1).
  21. Foxe JJ, Snyder AC. The Role of Alpha-Band Brain Oscillations as a Sensory Suppression Mechanism during Selective Attention. Front Psychol. 2011 2011-July-05;2(154):154.
  22. Kobayashi K. Effects of L-theanine on the release of alpha-brain waves in human volunteers. Journal of the Agricultural Chemical Society of Japan. 1998;72(2):153-7.
  23. Song CH, Jung JH, Oh JS, et al. Effects of theanine on the release of brain alpha waves in adult males. Korean J Nutr. 2003;36(9): 918-23.