Theanine

Summary sheet: Theanine

Theanine
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
WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section. Oral Dosage Threshold Common Heavy 50 - 75 - 175 - 300 - 500 mg Light Strong Threshold 50 - 75 mg Light 75 - 175 mg Common 175 - 300 mg Strong 300 - 500 mg Heavy 500 mg + Duration Total 3 - 6 hours[1] Onset 30 - 90 minutes[2] Peak 1 - 3 hours After effects 6 - 12 hours 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.

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

The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances and are more likely to induce a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.

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

Theanine is freely available to possess and distribute and is approved in most countries as a dietary supplement.

See also

• Nootropic
• Caffeine
• Glutamate

External links

• Theanine (Wikipedia)
• Theanine (Examine)

References