Last updated: August 30, 2021

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We live in an incredibly fast-paced and competitive society. Strenuous hours of mentally demanding work is the reality for most individuals, so it is important to stay active and creative whenever we get the opportunity. The question remains, is it possible to increase our intellectual performance without long-term side effects?

In this supplement guide, we are discussing L-theanine, a natural component generally found in green tea. It is known to promote concentration and minimize stress levels. Some say it is comparable to coffee, but without the jitters. Think it sounds too good to be true? Read on to find out!




Key Facts

  • L-theanine is an amino acid derived from tea.
  • It is useful for reducing anxiety as well as promoting better concentration and intellectual performance.
  • Before choosing the right L-theanine supplement, it is important to consider a few factors, such as dietary restrictions, the labeling and packaging of the product, the ingredients, and the value for money.

Our Selection: The Best L-theanine Supplements

The following products have been hand-picked from our Supplement Guide team. These particular L-theanine supplements stand out among the rest for their value for money, as well as other factors. With these options, there is something for everyone!

Shopping Guide: Everything You Should Know about L-theanine

L-theanine is a natural substance, derived from the tea plant. It has relaxing but not seating properties, and helps to promote intellectual performance in anxious individuals. L-theanine supplements are very popular for their effectiveness and lack of withdrawal symptoms.

What is L-theanine?

L-theanine is a natural substance with relaxing properties. Unlike essential amino acids such as L-arginine, this molecule is not part of a regular diet and is considered a non-essential amino acid. It is almost exclusively found in tea, although it can also be found in small amounts in some fungi. (3).

L-theanine is capable of affecting the brain directly. Its structure resembles that of the amino acid glutamine, a precursor to certain molecules in the nervous system (neurotransmitters) (5, 6).Thanks to its effects on brain tissue, L-theanine is able to regulate neuronal functions, having the following affects (7):

  • Alpha wave predominance:  Brain activity is extremely complex. Neurons communicate with each other through oscillating patterns of electrical energy, or brain waves. L-theanine may induce a relaxation-related neural behavior pattern without sedation, called "alpha waves"(7, 8, 9).
  • Increased production of dopamine and serotonin:  Dopamine and serotonin are known. neurotransmitters that influence mood. L-theanine helps to stimulate the production of these molecules, therefore improving mood and stimulating attention span and concentration (10, 11).
  • Changes in GABA concentration: γ-aminobutyric acid (GABA) is the quintessential inhibitory neurotransmitter, capable of promoting relaxation and preventing excess neuronal activation. It is believed that L-theanine consumption could increase neuronal GABA production, inducing a feeling of calm and relaxation.
  • Inhibition of glutamate release: Contrary to GABA, glutamate is an activating neurotransmitter. However, an excessive increase in this molecule can have harmful effects on neurons. L-theanine acts as a glutamate buffer, softening its effects on the nervous system. (12, 13, 14).
  • Reduction of oxidative damage: According to several different studies, L-theanine is able to bind to neuron receptors, preventing long-term neuronal damage and degeneration caused by excessive exposure to stressful situations (11, 15, 16).

Given these promising results, it is important to remember that most of the currently available studies will need to go through more trials before they can be fully accepted by the scientific community. One study found that people who drink green tea -- which is high in L-theanine -- had a lower risk of stroke. However it is unknown if it was actually the L-theanine in the green tea that produced the benefit. L- theanine could also boost the benefits -- and reduce side effects -- of some drugs for cancer treatment. But it is unknown yet whether L-theanine supplements would have these benefits in people. More research is needed to know for sure.

Isolated studies have also found possible effects of L-theanine such as (4):

  • Lowering blood pressure: Very high doses of L-theanine (1000 mg or higher) appear to be able to lower blood pressure in animal tests.
  • Lowering of cholesterol: Some studies in very early stages have found that the consumption of L-theanine could prevent the depositing of cholesterol in the arteries. Atherosclerosis, the main cause of cardiovascular disease, begins with the build up of cholesterol in the wall of the blood vessels.
  • Immunity booster: It is suspected that L-theanine could have some antibacterial functions, increasing the activity of cells in the immune system.
  • Antioxidant: L-theanine could inhibit the toxic effect of certain drugs on cells, demonstrating a potential antioxidant function.
Hannah CrumAuthor
"L-theanine crosses the blood-brain barrier and has positive psychoactive effects on the tea drinker. L-theanine plays a vital role in modulating the effect of the caffeine in tea, so that it is stimulating yet soothing; in contrast, the caffeine in coffee lacks the balancing presence of L-theanine and so delivers a jagged spike of stimulation that increases anxiety."

Is it possible to get the most out of L-theanine simply by drinking tea?

Clinical trials show that the benefits of L-theanine on the nervous system appear after consuming between 50 and 400 mg of this amino acid (18, 19, 20).In the following table, we outline the various amounts of L-theanine present in different types of tea(21):

Cup of tea (15 grams) Approximate L-theanine content (mg)
Green Tea. 150
White Tea. 135
Black Tea. 100
Earl Grey. 80
 Ceylon. 70
Sencha Green Tea. 45
Oolong. 15
Té Pu-Erh. 0

Depending on the type, brand, and temperature of the water, you would need to consume several cups of tea per day to obtain the benefits described by scientists. Because of this, many people turn to supplements, allowing them to consume the effective doses of this amino acid comfortably and easily.

How do you take L-theanine supplements?

L-theanine supplements can be purchased in the form of hard capsules, soft capsules, tablets, powder and chewable tablets, among others. As a general rule, it is recommended to follow the manufacturer's instructions to get the most out of the supplement. If you still have doubts about the use of L-theanine and how to take it, check out the following tips (18, 19, 20):

  • What dosage? Generally, a dose between 50 and 400mg per day is recommended. Although there is no official maximum limit, it is advised not to exceed the recommended daily dose.
  • What time?: L-theanine supplements can be very useful when taken before a mentally demanding task, as they can boost intellectual performance. They can also be taken in the morning or mid-afternoon to improve sleep quality and promote a state of relaxation.
  • Can you take it with food? There is really no data available as to the effect of food on L-theanine absorption. However, most manufacturers advise taking the supplements on an empty stomach.

The supplements generally start to take effect between 45 and 60 minutes after taking them, remaining active for approximately 15 hours. The characteristics of this component do not form a tolerance or resistance, therefore most individuals will not need to increase the dose over time. .

Organic Green Tea

The effect appears between 45 and 60 minutes after the intake of the supplement and remains active for approximately 15 hours.
(Source: Brent Hofacker: 35435332/ 123rf.com)

Is L-theanine better than caffeine?

L-theanine and caffeine share many of the same benefits. Both substances are relatively fast-acting and capable of increasing attention and concentration. However, consuming high amounts of caffeine can be accompanied by unpleasant symptoms such as nervousness and anxiety, which makes it a bad option for people who are already prone to these symptoms (23). On its own, L-theanine may improve a person’s attention and reaction times. In combination with caffeine, it may lead to improvements in their number skills and alertness. Caffeine is a stimulant, so it can help people stay alert and focused.

When it comes to L-theanine, some experts claim that it has the benefits of caffeine while lacking the side effects. This hypothesis seems to be supported by the appearance of alpha waves (which are responsible for attention and relaxation (16). The following table shows a comparison of the effects of both substances (23, 24, 25, 26, 27, 28, 29, 30):

Effect Caffeine L-theanine Caffeine + L-theanine
Energy Increases. Neutral. Increase.
Attention Increases. Increase. Increase.
Memery Slight improvement. Slight improvement. Improvement.
Relaxation Decreases. Increases. Increases.
Sleep Decreases. Increases. Neutral.
Anxiety increases. decreases. Neutral.
Blood pressure Increases. Normal. Normal.

If you need fast energy, caffeine is your best option. L-theanine will be most useful when it comes to tasks where you need attention and a clear mind. The combination of caffeine and L-theanine brings the best of both substances, giving you better focus without affecting your sleep patterns or bringing anxiety. These benefits may result from the specific effects that the amino acid has on brain chemicals that play a role in sleep.

A 2018 study found that people reported having greater sleep satisfaction after taking 450–900 mg of L-theanine daily for 8 weeks. The study participants had generalized anxiety disorder and were taking antidepressants.

Generally, L-theanine and caffeine supplements have a 1:2 ratio, always doubling the amount of L-theanine to the caffeine. For example, you can combine a 100mg dose of caffeine with a 200mg dose of L-theanine. Caffeine can be taken as a drink (one cup of black coffee contains about 80mg) or as a supplement.

What precautions should I be aware of when taking L-theanine supplements?

To date, there are no real adverse effects related to taking large amounts of L-theanine, even at doses much higher than those recommended. That being said, it is still not recommended to exceed 400mg of this amino acid per day. L-theanine should not be used to treat psychiatric disorders and should never be a substitute for physician prescribed treatment (31).

The nootropic effect of L-theanine appears between 45 to 60 minutes after taking the supplement.

There is a lack of reliable information when it comes to the long-term health effects of this supplement for pregnant and lactating women, people under the age of eighteen or individuals undergoing chemotherapy (31, 32). In these cases, taking L-theanine without medical supervision is strongly discouraged.

There is conflicting data when it comes to the relationship between L-theanine and the presents of seizures (33). Furthermore, people taking antihypertensive drugs may have altered potency while taking the supplement (34). For this reason, people suffering from epilepsy or hypertension are recommended not to consume this substance without supervision.

L-theanine supplements are considered safe to use for healthy people. Gastrointestinal complaints and headaches have been described, which were alleviated after reducing the dosage. This substance could also lower blood pressure in predisposed people, which could cause dizziness.

Michael J Breus Ph.D.Sleep Specialist”
"L-theanine may lower blood pressure, and combining this supplement with other blood-pressure lowering supplements may cause blood pressure to drop too much.".

Buyer's Guide

There are plenty of L-theanine supplements available on the market. But how do you know which is the best one for you? The following purchase criteria will help you make the smartest decision, without needing to spend hours searching online.

Dietary Restrictions

L-theanine is derived from the extract of Camellia Sinensis, the tea plant. In its pure form, this supplement is suitable for vegans, celiacs, lactose intolerant individuals, and those allergic to soy. However, the bonding agents used to combine the ingredients could possibly include undesirable products. Always check the labeling before buying if you have certain dietary restrictions.

Labels

A good quality supplement brand will include the concentration of L-theanine included in each dose on its label. It should also include a list of ingredients and information about the allergens contained in the product. This data should be clear and perfectly visible and written in plain English.

L-theanine can be sold under alternative names. The term "theanine" is also widely used and refers to the same amino acid. Theanine and L-theanine can be used interchangeably. Another less popular, but equally valid name is gamma glutamylethymide (5-N-ethyl-glutamine).

Packaging

L-theanine supplements should be sold in perfectly sealed containers that keep the product in the best possible condition. If the item is purchased online, shipping should take into account the necessary precautions, avoiding light, odors, and knocks.

thenina on a bowl

To date, no adverse effects related to an exaggerated intake of L-theanine have been described, even at doses much higher than those recommended.
(Source: Anna Pustynnikova: 107428818/ 123rf.com)

Expiration Date

No toxic or dangerous effects have been described due to the consumption of L-theanine after its expiration date. However, taking expired L-theanine supplements may be less potent and may not give the desired effects compared to taking it before its use-by date.

Summary

L-theanine is a supplement that is very much appreciated by those who need to perform their best everyday, which is most of us. This completely natural substance derived from tea could revolutionize your day-to-day life, helping you achieve the mindfulness that is needed for studying and for work.

The best kept secret of the tea aficionados  is now available to you! L-theanine may affect the levels of certain chemicals in the brain. These include serotonin and dopamine, which influence mood, sleep, and emotion, and cortisol, which helps the body deal with stress. Consumed individually or combined with morning coffee, L-theanine will increase your concentration levels and help to promote productivity.

If you liked our guideline on L-theanine and found it helpful, please leave and comment and share with your friends!

(Source of featured image: Cseh Ioan: 51629488/ 123rf.com)

References (34)

1. Breus MJ. What You Need to Know About L-theanine [Internet]. Psychology Today. 2017.
Source

2. Pescador D. Drugs to Mix with Coffee eldiario.es. 2017
Source

3. Chu DC, Okubo T, Nagato Y, Yokogoshi H. L-theanine - A unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Technol. 1999;10(6–7):199–204.
Source

4. Eschenauer G, Sweet B V. Pharmacology and therapeutic uses of theanine. Am J Heal Pharm. 2006;63(1).
Source

5. Petroff OAC. GABA and glutamate in the human brain. Neuroscientist [Internet]. 2002 Dec [cited 2019 Oct 7];8(6):562–73.
Source

6. Başkan MH, Aydın M. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride. Spectrochim Acta A Mol Biomol Spectrosc [Internet]. 2013 Aug [cited 2019 Oct 7];112:280–2.
Source

7. Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state.: Discovery Service for Endeavour College of Natural Health Library. Asia Pac J Clin Nutr [Internet]. 2008 [cited 2019 Oct 6];17(S1):167–8.
Source

8. Klimesch W. Alpha-band oscillations, attention, and controlled access to stored information. Vol. 16, Trends in Cognitive Sciences. 2012. p. 606–17.
Source

9. Roohi-Azizi M, Azimi L, Heysieattalab S, Aamidfar M. Changes of the brain’s bioelectrical activity in cognition, consciousness, and some mental disorders. Vol. 31, Medical Journal of the Islamic Republic of Iran. Iran University of Medical Sciences; 2017. p. 307–12.
Source

10. Shen M, Yang Y, Wu Y, Zhang B, Wu H, Wang L, et al. L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions. Phytother Res [Internet]. 2019 Feb [cited 2019 Oct 8];33(2):412–21.
Source

11. Nathan PJ, Lu K, Gray M, Oliver C. The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother [Internet]. 2006 [cited 2019 Oct 8];6(2):21–30.
Source

12. Yamada T, Terashima T, Okubo T, Juneja LR, Yokogoshi H. Effects of theanine, r-glutamylethylamide, on neurotransmitter release and its relationship with glutamic acid neurotransmission. Nutr Neurosci [Internet]. 2005 Aug [cited 2019 Oct 8];8(4):219–26.
Source

13. Egashira N, Hayakawa K, Osajima M, Mishima K, Iwasaki K, Oishi R, et al. Involvement of GABA(A) receptors in the neuroprotective effect of theanine on focal cerebral ischemia in mice. J Pharmacol Sci [Internet]. 2007 Oct [cited 2019 Oct 8];105(2):211–4.
Source

14. Zhou Y, Danbolt NC. Glutamate as a neurotransmitter in the healthy brain. Vol. 121, Journal of Neural Transmission. 2014. p. 799–817.
Source

15. Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr. 2016 Sep 1;59(2):93–9.
Source

16. Lardner AL. Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders. Nutr Neurosci [Internet]. 2014 Jul [cited 2019 Oct 8];17(4):145–55.
Source

17. Suliman NA, Mat Taib CN, Mohd Moklas MA, Adenan MI, Hidayat Baharuldin MT, Basir R. Establishing Natural Nootropics: Recent Molecular Enhancement Influenced by Natural Nootropic. Vol. 2016, Evidence-based Complementary and Alternative Medicine. Hindawi Limited; 2016.
Source

18. Higashiyama A, Htay HH, Ozeki M, Juneja LR, Kapoor MP. Effects of l-theanine on attention and reaction time response. J Funct Foods. 2011 Jul;3(3):171–8.
Source

19. Lu K, Gray MA, Oliver C, Liley DT, Harrison BJ, Bartholomeusz CF, et al. The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum Psychopharmacol. 2004 Oct;19(7):457–65.
Source

20. Kapoor M, Lyon M, Juneja L. The effects of L-theanine on objective sleep quality in boys with attention deficit hyperactivity disorder. Altern Med Rev [Internet]. 2011 [cited 2019 Oct 6];16(4):348–54.
Source

21. Boros K, Jedlinszki N, Csupor D. Theanine and Caffeine content of infusions prepared from commercial tea samples. Pharmacogn Mag. 2016 Jan 1;12(45):75–8.
Source

22. NIH. L-theanine [Internet]. Pubchem.ncbi.nlm.nih.gov. 2019.
Source

23. Lara DR. Caffeine, mental health, and psychiatric disorders. J Alzheimers Dis [Internet]. 2010 [cited 2019 Oct 9];20 Suppl 1:S239-48.
Source

24. Kelly SP, Gomez-Ramirez M, Montesi JL, Foxe JJ. L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. J Nutr [Internet]. 2008 Aug [cited 2019 Oct 6];138(8):1572S-1577S.
Source

25. Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci [Internet]. 2008 Aug [cited 2019 Oct 6];11(4):193–8.
Source

26. Giesbrecht T, Rycroft JA, Rowson MJ, De Bruin EA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci [Internet]. 2010 [cited 2019 Oct 6];13(6):283–90.
Source

27. Sherman SM, Buckley TP, Baena E, Ryan L. Caffeine enhances memory performance in young adults during their non-optimal time of day. Front Psychol. 2016 Nov 14;7(NOV).
Source

28. Blaise JH, Park JE, Bellas NJ, Gitchell TM, Phan V. Caffeine consumption disrupts hippocampal long-term potentiation in freely behaving rats. Physiol Rep. 2018 Mar 1;6(5).
Source

29. Erikson GC, Hager LB, Houseworth C, Dungan J, Petros T, Beckwith BE. The effects of caffeine on memory for word lists. Physiol Behav [Internet]. 1985 Jul [cited 2019 Oct 9];35(1):47–51.
Source

30. Yoto A, Motoki M, Murao S, Yokogoshi H. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012;31:28.
Source

31. Theanine: Health Benefits, Uses, Side Effects, Dosage & Interactions [Internet]. [cited 2019 Oct 9].
Source

32. Yan Q, Tong H, Tang S, Tan Z, Han X, Zhou C. L-Theanine administration modulates the absorption of dietary nutrients and expression of transporters and receptors in the intestinal mucosa of rats. Biomed Res Int. 2017;2017.
Source

33. Schallier A, Vermoesen K, Loyens E, Van Liefferinge J, Michotte Y, Smolders I, et al. L-Theanine intake increases threshold for limbic seizures but decreases threshold for generalized seizures. Nutr Neurosci [Internet]. 2013 Mar [cited 2019 Oct 6];16(2):78–82.
Source

34. Adhikary R, Mandal V. L-theanine: A potential multifaceted natural bioactive amide as health supplement. Vol. 7, Asian Pacific Journal of Tropical Biomedicine. Hainan Medical University; 2017. p. 842–8.
Source

Why you can trust me?

Revista de divulgación científica (Psychology Today)
Breus MJ. What You Need to Know About L-theanine [Internet]. Psychology Today. 2017.
Go to source
Artículo periodístico
Pescador D. Drugs to Mix with Coffee eldiario.es. 2017
Go to source
Publicación científica
Chu DC, Okubo T, Nagato Y, Yokogoshi H. L-theanine - A unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Technol. 1999;10(6–7):199–204.
Go to source
Artículo científico
Eschenauer G, Sweet B V. Pharmacology and therapeutic uses of theanine. Am J Heal Pharm. 2006;63(1).
Go to source
Artículo científico
Petroff OAC. GABA and glutamate in the human brain. Neuroscientist [Internet]. 2002 Dec [cited 2019 Oct 7];8(6):562–73.
Go to source
Artículo científico
Başkan MH, Aydın M. Electron paramagnetic resonance studies of gamma-irradiated DL-alanine ethyl ester hydrochloride, L-theanine and L-glutamic acid dimethyl ester hydrochloride. Spectrochim Acta A Mol Biomol Spectrosc [Internet]. 2013 Aug [cited 2019 Oct 7];112:280–2.
Go to source
Artículo científico
Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state.: Discovery Service for Endeavour College of Natural Health Library. Asia Pac J Clin Nutr [Internet]. 2008 [cited 2019 Oct 6];17(S1):167–8.
Go to source
Artículo científico
Klimesch W. Alpha-band oscillations, attention, and controlled access to stored information. Vol. 16, Trends in Cognitive Sciences. 2012. p. 606–17.
Go to source
Artículo científico
Roohi-Azizi M, Azimi L, Heysieattalab S, Aamidfar M. Changes of the brain’s bioelectrical activity in cognition, consciousness, and some mental disorders. Vol. 31, Medical Journal of the Islamic Republic of Iran. Iran University of Medical Sciences; 2017. p. 307–12.
Go to source
Artículo científico
Shen M, Yang Y, Wu Y, Zhang B, Wu H, Wang L, et al. L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions. Phytother Res [Internet]. 2019 Feb [cited 2019 Oct 8];33(2):412–21.
Go to source
Artículo científico
Nathan PJ, Lu K, Gray M, Oliver C. The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother [Internet]. 2006 [cited 2019 Oct 8];6(2):21–30.
Go to source
Artículo científico
Yamada T, Terashima T, Okubo T, Juneja LR, Yokogoshi H. Effects of theanine, r-glutamylethylamide, on neurotransmitter release and its relationship with glutamic acid neurotransmission. Nutr Neurosci [Internet]. 2005 Aug [cited 2019 Oct 8];8(4):219–26.
Go to source
Artículo científico
Egashira N, Hayakawa K, Osajima M, Mishima K, Iwasaki K, Oishi R, et al. Involvement of GABA(A) receptors in the neuroprotective effect of theanine on focal cerebral ischemia in mice. J Pharmacol Sci [Internet]. 2007 Oct [cited 2019 Oct 8];105(2):211–4.
Go to source
Artículo científico
Zhou Y, Danbolt NC. Glutamate as a neurotransmitter in the healthy brain. Vol. 121, Journal of Neural Transmission. 2014. p. 799–817.
Go to source
Artículo científico
Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr. 2016 Sep 1;59(2):93–9.
Go to source
Artículo científico
Lardner AL. Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders. Nutr Neurosci [Internet]. 2014 Jul [cited 2019 Oct 8];17(4):145–55.
Go to source
Artículo científico
Suliman NA, Mat Taib CN, Mohd Moklas MA, Adenan MI, Hidayat Baharuldin MT, Basir R. Establishing Natural Nootropics: Recent Molecular Enhancement Influenced by Natural Nootropic. Vol. 2016, Evidence-based Complementary and Alternative Medicine. Hindawi Limited; 2016.
Go to source
Ensayo clínico (doble ciego)
Higashiyama A, Htay HH, Ozeki M, Juneja LR, Kapoor MP. Effects of l-theanine on attention and reaction time response. J Funct Foods. 2011 Jul;3(3):171–8.
Go to source
Ensayo clínico
Lu K, Gray MA, Oliver C, Liley DT, Harrison BJ, Bartholomeusz CF, et al. The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum Psychopharmacol. 2004 Oct;19(7):457–65.
Go to source
Ensayo clínico
Kapoor M, Lyon M, Juneja L. The effects of L-theanine on objective sleep quality in boys with attention deficit hyperactivity disorder. Altern Med Rev [Internet]. 2011 [cited 2019 Oct 6];16(4):348–54.
Go to source
Artículo científico
Boros K, Jedlinszki N, Csupor D. Theanine and Caffeine content of infusions prepared from commercial tea samples. Pharmacogn Mag. 2016 Jan 1;12(45):75–8.
Go to source
Ficha técnica. (Base de datos NIH)
NIH. L-theanine [Internet]. Pubchem.ncbi.nlm.nih.gov. 2019.
Go to source
Artículo científico
Lara DR. Caffeine, mental health, and psychiatric disorders. J Alzheimers Dis [Internet]. 2010 [cited 2019 Oct 9];20 Suppl 1:S239-48.
Go to source
Artículo científico
Kelly SP, Gomez-Ramirez M, Montesi JL, Foxe JJ. L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. J Nutr [Internet]. 2008 Aug [cited 2019 Oct 6];138(8):1572S-1577S.
Go to source
Artículo científico
Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci [Internet]. 2008 Aug [cited 2019 Oct 6];11(4):193–8.
Go to source
Artículo científico
Giesbrecht T, Rycroft JA, Rowson MJ, De Bruin EA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci [Internet]. 2010 [cited 2019 Oct 6];13(6):283–90.
Go to source
Artículo científico
Sherman SM, Buckley TP, Baena E, Ryan L. Caffeine enhances memory performance in young adults during their non-optimal time of day. Front Psychol. 2016 Nov 14;7(NOV).
Go to source
Artículo científico
Blaise JH, Park JE, Bellas NJ, Gitchell TM, Phan V. Caffeine consumption disrupts hippocampal long-term potentiation in freely behaving rats. Physiol Rep. 2018 Mar 1;6(5).
Go to source
Artículo científico
Erikson GC, Hager LB, Houseworth C, Dungan J, Petros T, Beckwith BE. The effects of caffeine on memory for word lists. Physiol Behav [Internet]. 1985 Jul [cited 2019 Oct 9];35(1):47–51.
Go to source
Artículo científico
Yoto A, Motoki M, Murao S, Yokogoshi H. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012;31:28.
Go to source
Página web (divulgación médica)
Theanine: Health Benefits, Uses, Side Effects, Dosage & Interactions [Internet]. [cited 2019 Oct 9].
Go to source
Artículo científico
Yan Q, Tong H, Tang S, Tan Z, Han X, Zhou C. L-Theanine administration modulates the absorption of dietary nutrients and expression of transporters and receptors in the intestinal mucosa of rats. Biomed Res Int. 2017;2017.
Go to source
Artículo científico
Schallier A, Vermoesen K, Loyens E, Van Liefferinge J, Michotte Y, Smolders I, et al. L-Theanine intake increases threshold for limbic seizures but decreases threshold for generalized seizures. Nutr Neurosci [Internet]. 2013 Mar [cited 2019 Oct 6];16(2):78–82.
Go to source
Artículo científico
Adhikary R, Mandal V. L-theanine: A potential multifaceted natural bioactive amide as health supplement. Vol. 7, Asian Pacific Journal of Tropical Biomedicine. Hainan Medical University; 2017. p. 842–8.
Go to source
Reviews