Theanine
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Summary sheet: Theanine |
Theanine | |||||||||||||||||||||||||||||
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Chemical Nomenclature | |||||||||||||||||||||||||||||
Common names | Theanine, L-Theanine, L-γ-glutamylethylamide and N5-ethyl-L-glutamine | ||||||||||||||||||||||||||||
Systematic name | N-ethyl-L-glutamine; (2S)-2-ammonio-5-(ethylamino)-5-oxopentanoate | ||||||||||||||||||||||||||||
Class Membership | |||||||||||||||||||||||||||||
Psychoactive class | Nootropic | ||||||||||||||||||||||||||||
Chemical class | Amino acid analogue | ||||||||||||||||||||||||||||
Routes of Administration | |||||||||||||||||||||||||||||
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L-Theanine (also known as Theanine, L-γ-glutamylethylamide and N5-ethyl-L-glutamine) is an analog of the amino acids of glutamate and glutamine. It was discovered as a constituent of green tea in 1949 and in 1950 was isolated from gyokuro leaves, which have high theanine content.[3]
The appearance of the name "theanine" without a prefix is understood to imply the L-enantiomer, which is the form found in fresh teas and in some, but not all dietary supplements. The opposite D-enantiomer has far less studied pharmacologic properties, but is present in racemic chemical preparations, and substantially in some studied theanine supplements.
This compound is used as a nootropic for its calming and relaxing properties. It is often taken in combination with caffeine as it has been shown to mitigate its negative aspects, such as anxiety, increased blood pressure and diminished sleep quality, while possibly improving upon the positive aspects.[4][5][6][7] Its ability to enhance attention has been repeatedly verified.[8][9][10][11][12][13][14]
A recent systematic review of the effects of theanine and caffeine has confirmed that the combination seems to improve aspects of attention.[15] The combination of L-theanine and caffeine may improve attention more than caffeine alone.[16][17]
Chemistry
Theanine, or N-ethyl-L-glutamine, is an amino acid analogue of L-glutamine. Its structure is comprised of a five carbon straight chain carboxylic acid called pentanoic acid, which is bonded to an amino group at R2, and an additional ketone group at R5. Also substituted at R5 of the pentanoic group is an ethylamino chain connected at its amino constituent. Theanine is understood to refer to the levorotary enantiomer, which is well documented, rather than the relatively unresearched dextrorotary enantiomer.
Pharmacology
Theanine is structurally similar to the excitatory neurotransmitter glutamate, and in accordance, binds to glutamate receptors, though with much lower affinity in comparison. Specifically, it binds to ionotropic glutamate receptors including the AMPA and kainate receptors and, to a lesser extent, the NMDA receptor.[18][19][20][21] It acts as an antagonist of the former two sites[22] and as an agonist of the latter site.[23] In addition, it inhibits glutamine transporters and glutamate transporters, and thus acts as reuptake inhibitor of glutamine and glutamate.[24][25][26]
Theanine increases dopamine, GABA, and glycine levels in various areas of the brain.[27][28][29][30] It also affects serotonin in a manner which is still a matter of debate in the scientific community, with separate studies showing increases and decreases in brain serotonin levels using similar experimental protocols.[31][32]
These various changes in neurotransmitter levels contribute to the calming and nootropic properties of theanine.
Subjective effects
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), a literature based on anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be treated with a healthy amount of skepticism. It is worth noting that these effects will not necessarily occur in a consistent or reliable manner, although higher doses are more likely to induce the full spectrum of effects. Likewise, adverse effects become much more likely with higher doses and may include serious injury or death.
Physical effects 
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- Sedation & Stimulation - Theanine is mildly stimulating at light to common dosages but becomes sedating starting with strong doses at around 300mg.
- Muscle relaxation - At heavy doses, theanine induces muscle relaxation that is vaguely comparable to that of the relaxation produced by benzodiazepines.
- Spontaneous bodily sensations - Theanine can produce a physical feeling of glowing warmth that is present throughout one's body at higher doses.
- Headaches - Headaches are usually only reported at high doses, well above 200mg.
Cognitive effects 
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- Anxiety suppression - Theanine produces anxiolytic effects which are comparable to a mild dose of a benzodiazepine but without the accompanying disinhibition.
- Mindfulness - Some users report that theanine can produce uniquely distinct states of mindfulness.
- Memory enhancement[33] - Theanine has been shown to improve memory and attention in subjects with mild cognitive impairments.
- Addiction suppression - Some anecdotal reports suggest that theanine may mitigate some of the effects of opioid withdrawal.
- Thought organization
- Analysis enhancement
- Focus enhancement
- Motivation enhancement
Experience reports
There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:
Toxicity and harm potential
Theanine is non-addictive, is not known to cause brain damage, and has an extremely low toxicity relative to dose.[citation needed] There are relatively few physical side effects associated with acute theanine exposure. Various studies have shown that in reasonable doses in a careful context, it presents no negative cognitive, psychiatric or toxic physical consequences.[citation needed]
It is strongly recommended that one use harm reduction practices when using this substance.
Tolerance and addiction potential
Theanine is not habit-forming.
Tolerance to the effects of theanine are built up after prolonged and repeated usage. After noticeable tolerance has been built, it takes about 5 days for tolerance to be reduced by half and 10 days return to baseline. Theanine presents cross-tolerance with no other known compounds, meaning that after the consumption of theanine all other psychoactive compounds will not have a reduced effect.
Legal status
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Theanine is freely available to possess and distribute and is approved in most countries as a dietary supplement.
- Canada Theanine is available as a dietary supplement and is freely available to possess and distribute in Canada.[citation needed]
See also
External links
References
- ↑ Kinetics of L-Theanine Uptake and Metabolism in Healthy Participants Are Comparable after Ingestion of L-Theanine via Capsules and Green Tea | http://jn.nutrition.org/content/142/12/2091
- ↑ Kinetics of L-Theanine Uptake and Metabolism in Healthy Participants Are Comparable after Ingestion of L-Theanine via Capsules and Green Tea | http://jn.nutrition.org/content/142/12/2091
- ↑ Components of Gyokuro | http://www.ippodo-tea.co.jp/en/tea/gyokuro_02.html
- ↑ The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/22214254
- ↑ The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/15378679
- ↑ L-Theanine reduces psychological and physiological stress responses (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/16930802
- ↑ Acute effects of theanine, caffeine and theanine-caffeine combination on attention | www.ncbi.nlm.nih.gov/pubmed/26869148
- ↑ The combined effects of L-theanine and caffeine on cognitive performance and mood (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/18681988
- ↑ The effects of L-theanine, caffeine and their combination on cognition and mood (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/18006208
- ↑ L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/20079786
- ↑ L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/18641209
- ↑ The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/21040626
- ↑ Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/22326943
- ↑ Acute effects of theanine, caffeine and theanine-caffeine combination on attention (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/26869148
- ↑ Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis | www.ncbi.nlm.nih.gov/pubmed/24946991
- ↑ The combined effects of L-theanine and caffeine on cognitive performance and mood (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/18681988
- ↑ The effects of L-theanine, caffeine and their combination on cognition and mood (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/18006208
- ↑ The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/17182482
- ↑ Inhibition by theanine of binding of [3H]AMPA, [3H]kainate, and [3H]MDL 105,519 to glutamate receptors (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/12596867
- ↑ Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/21477654
- ↑ Neuroprotective effects of the green tea components theanine and catechins (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/12499631
- ↑ Neuroprotective effects of the green tea components theanine and catechins (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/12499631
- ↑ Behavioral and molecular evidence for psychotropic effects in L-theanine (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/21861094
- ↑ Neuroprotective effects of the green tea components theanine and catechins (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/12499631
- ↑ Inhibition of glutamate transporter by theanine enhances the therapeutic efficacy of doxorubicin (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/11325559
- ↑ Theanine and glutamate transporter inhibitors enhance the antitumor efficacy of chemotherapeutic agents (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/14643924
- ↑ The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/17182482
- ↑ Behavioral and molecular evidence for psychotropic effects in L-theanine (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/21861094
- ↑ Theanine, r-glutamylethylamide, increases neurotransmission concentrations and neurotrophin mRNA levels in the brain during lactation (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/17904164
- ↑ Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/9566605
- ↑ Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/9566605
- ↑ Theanine-induced reduction of brain serotonin concentration in rats (PubMed.gov / NCBI) | https://www.ncbi.nlm.nih.gov/pubmed/9614715
- ↑ A combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled study. (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/21303262