L-Theanine

6

Energy

7.0 /10

Endurance

7.0 /10

Relaxation

4.0 /10

L-Theanine

Boost Energy
Cognitive
Improve Focus
Improve Memory
Pre Workout
Weight Loss
Nootropics
Mood Support

Description

Summary

L-theanine, also known as N-ethyl-L-glutamine, is a major non-protein, water soluble [1] amino acid commonly found in green tea [2; 3].

Mechanism and interactions

Once consumed, L-theanine rapidly interacts with the intestinal tract, where it is absorbed, as well as being transported into the brain [4;5]. Within 5 hours L-theanine reaches its maximum level, where it then lasts for 24 hours – having exited the kidneys, liver and brain [6].

Benefits and Effects

L-theanine has anti-tumour, anti-diabetes, anti-hypertension and anti-stress effects [7; 8]. Additionally, L-theanine prevents nerve cell damage and protects the liver from damage [7].

L-theanine and major depressive disorder (MDD)

In a more recent study assessing the effect of L-theanine on patients with depression, L-theanine – in a 250mg/day dose administered over 8 weeks – showed a beneficial outcome in depressive symptoms: anxiety, sleep disturbance and cognitive impairment in all patients [9].

L-theanine and ADHD

One study found that L-theanine in studying ADHD, given in a 400mg dose to 8-12-year-old boys, was effective in improving sleep quality [10]. Researchers of this study suggested the importance of considering a 400mg, safe dose in treating childhood ADHD [10].

L-theanine effects on sleep

L-theanine was found to improve sleep quality in patients suffering from schizophrenia [11]. An investigation into ADHD-related sleep disorders found that L-theanine did not produce a significant change in total sleep time; however, it did significantly increase sleep efficiency along with a reduction in nocturnal activity [12].

L-theanine and blood pressure

Animal work has found that L-theanine can reduce blood pressure in hypersensitive rats [13]. This has largely been attributed to the way L-theanine interacts with the autonomic nervous syste, (ANS), where it carries out anti-stress activities [13].

Dosage

Typical doses of between 50-200mg daily is most commonly reported [14]. Studies in rats have demonstrated that up to 4 g/kg per day – considered a high L-theanine dose – had a non-toxic outcome on food intake, body weight and morbidity [7]. Other studies have reported that a high dose of 400mg daily L-theanine is safe, tolerable and effective [10]. In addition, a 200-400mg dose of L-theanine reported a decrease in anxiety and stress in healthy participants [15].

Side effects

Results of acute and toxicity have shown safety even if a high dose is consumed [5]. Toxicological descriptions have also reported the absence of negative side effects in animal studies investigating L-theanine [4].

Stacks

Research has consistently used L-theanine and caffeine in low, moderate and high doses. In this manner, it has been shown that 100mg L-theanine stacked with 50mg caffeine has positive outcomes on attention [15].

Safety

L-theanine is approved as generally regarded as safe (GRAS) by the Food and Drug Administration (FDA) [8]. In addition, the FDA has suggested that the daily amount of L-theanine should not exceed 1200mg.

Sources

Sources

  1. Jackson Williams, Jane Kellett, Paul Daniel Roach, Andrew McKune, Duane Mellor, Jasckson Thomas and Nenad Naumovski, 2016. L-theanine as a Functional Food Additive: It Role in Disease Prevention and Health Promotion. Beverages, 2:13.
  2. Kenta Kimura, Makoto Ozeki, Lekh Raj Juneja, Hideki Ohira, 2007. L-Theanine reduces psychological and physiological stress responses. Biological Psychology, 74.
  3. Crystal F. Haskell, David O. Kennedy, Anthea L. Milne, Keith A. Wesnes, Andrew B. Scholey, 2008. The effects of L-theanine, caffeine and their combination on cognition and mood. Biological Psychology, 77.
  4. Pradeep J. Nathan, Kristy Lu, M. Gray and C. Oliver, 2009. The Neuropharmacology of L-Theanine (N-Ethyl-L-Glutamine): A Possible Neuroprotective and Cognitive Enhancing Agent. Journal of Herbal Pharmacotherapy, 6:2.
  5. Duygu Turkozu and Nevin Sanlier, 2017. L-theanine, unique amino acid of tea, and its metabolism, health effects and safety. Critical Reviews in Food Science and Nutrition, 57:8.
  6. Anne L. Lardner, 2013. Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders. Nutritional Neurosience.
  7. Yue-Rong Liang, Chang Liu, Li-Ping Xiang and Xin-Qiang Zheng, 2015. Health Benefits of Theanine in Green Tea: A Review. Tropical Journal of Pharmaceutical Research, 14:10.
  8. Wanmeng Mu, Tao Zhang, Bo Jiang, 2015. An overview of biological production of L-theanine. Biotechnology Advances, 33.
  9. Shinsuke Hidese, Miho Ota, Chisato Wakabayashi, Takamasa Noda, Hayato Ozawa, Tsutomu Okubo and Hiroshi Kunugi, 2017. Effects of chronic L-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatrica, 29.
  10. Michael R. Lyon, Mahendra P. Kapoor, Lekh R. Juneja, 2011. The Effects of L-Theanine (Suntheanine) on Objective Sleep Quality in Boys with Attention Deficit Hyperactivity Disorder (ADHD): A Randomised, Double-blind, Placebo-controlled Clinical Trial. Alternative Medicine Review, 16:4.
  11. Miho Ota, Chisato Wakabayashi, Noriko Sato, Hiroaki Hori, Kotaro Hattori, Toshiya Teraishi, Hayato Ozawa, Tsutomu Okubo and Hiroshi Kunugi, 2015. Effect of L-theanine on glutamatergic function in patients with schizophrenia. Acta Neuropsychiatrica, 27.
  12. Jessica R. Barrett, Derek K. Tracy, and Giovanni Giaroli, 2013. To Sleep or Not to Sleep: A Systematic Review of the Literature of Pharmacological Treatments of Insomnia in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder. Journal of Child and Adolescent Psychopharmacology, 23:10.
  13. Ai Yoto, Mao Motoki, Satu Murao and Hidehiko Yokogoshi, 2012. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. Journal of Physiological Anthropology, 31:28.
  14. Alternative Therapies, 2006. Pharmacology and therapeutic uses of theanine. American Journal of Health System Pharmacology, 63.
  15. Lisa Scheid, Sabine Ellinger, Birgit Altehekd, Hannes Herholz, Jorg Ellinger, Thomas Henn, Hans-Peter Helfrich and Peter Stehle, 2012. Kinetics of L-Theanine Uptake and Metabolism in Healthy Participants Are Comparable after Ingestion of L-Theanine via Capsules and Green Tea. The Journal of Nutrition.
  16. Gail N. Owen, Holly Parnell, Eveline A. De Bruin, Jane A. Rycroft, 2008. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutritional Neuroscience, 11:4.
Also known as:Theanine, 5-N-Ethyl-Glutamine
Type:Adaptogen
Good for: , , , , , , ,
Stacks well with: Coming soon…
Typical dose:100-200 mg
Half Life :2.5 - 4.5 Hours
L-Theanine

L-Theanine

Boost Energy
Cognitive
Improve Focus
Improve Memory
Pre Workout
Weight Loss
Nootropics
Mood Support