This is an unofficial archive of PsychonautWiki as of 2025-08-11T15:14:44Z. Content on this page may be outdated, incomplete, or inaccurate. Please refer to the original page for the most up-to-date information.
Theanine
Revision as of 02:53, 21 April 2019 by >Tracer([https://www.erowid.org/experiences/subs/exp_Theanine.shtml Erowid Experience Vaults: Theanine])
It may contain incorrect information, particularly with respect to dosage, duration, subjective effects, toxicity and other risks. It may also not meet PW style and grammar standards.
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.[2]
Theanine
Chemical Nomenclature
Common names
Theanine, L-Theanine, L-γ-glutamylethylamide and N5-ethyl-L-glutamine
WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.
DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.
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.
A recent systematic review of the effects of theanine and caffeine has confirmed that the combination seems to improve aspects of attention.[14] The combination of L-theanine and caffeine may improve attention more than caffeine alone.[15][16]
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 neurotransmitterglutamate, 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.[17][18][19][20] It acts as an antagonist of the former two sites[21] and as an agonist of the latter site.[22] In addition, it inhibits glutamine transporters and glutamate transporters, and thus acts as reuptake inhibitor of glutamine and glutamate.[23][24][25]
Theanine increases dopamine, GABA, and glycine levels in various areas of the brain.[26][27][28][29] 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.[30][31]
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), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWikicontributors. As a result, they should be viewed with a healthy degree of skepticism.
It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.
Muscle relaxation - At heavy doses, theanine induces muscle relaxation that are vaguely comparable to that of the relaxation produced by benzodiazepines.
Spontaneous physical sensations - Theanine can produce a physical feeling of glowing warmth that is present throughout one's body at higher doses.
Headaches - This effect is only reported at high doses, well above 200mg.
Cognitive effects
Anxiety suppression - Theanine produces anxiolytic effects which are comparable to a mild dose of a benzodiazepine but without the accompanying disinhibition.
Mindfulness - Theanine induces distinctive states of mindfulness more consistently than perhaps any other known psychoactive compound.
Memory enhancement[32] - Theanine has been shown to improve memory and attention in subjects with mild cognitive impairments.
There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:
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]
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.
↑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
↑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
↑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 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 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
↑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
↑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
↑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