Theanine is an amino acid commonly found in Green Tea. It is commonly taken as a supplement for its nootropic benefits.
What Is Theanine?
Theanine is an amino acid found in some plants including the basidiomycete mushroom and green tea. This nootropic is known to be a stress reliever and relaxant that also carries a number of nootropic properties. In 1964 theanine was approved by the Japanese Ministry of Health and Welfare for universal consumption. It is currently available in the United States as a dietary supplement and is confirmed by the FDA for being “Generally recognized as safe” 
Certain beverage manufacturers have begun to manufacture drinks containing thiamine and are currently marketing them as focus and concentration aids.  Other manufacturers are marketing them for their ability to help people relax. 
Theanine Dosage Information
Even though there is no standard dose for thiamine, many sources indicate a dose of 200-300mg should be taken as needed. Other people have found that they must take as much as 500mg at a time to notice an effect. I recommend you start with a 200mg dose and work your way up as needed. It will take 30-60 minutes for the dose to take effect and may last from 3-4 hours.
How Does Theanine Work?
- Acts as an analog to glutamine and glutamate 
- Significantly increased levels of serotonin and dopamine in the brain 
- Increases levels of the inhibitory transmitter GABA 
- Promotes alpha wave production in the brain.  Alpha waves play an important role in coordination and communication within the brain. 
Safety and Side Effects of Theanine
Taking theanine with medications for high blood pressure may cause your blood pressure to drop too low. Theanine may also decrease the effectiveness of certain stimulant medications. 
Below are some of the most commonly asked questions about Theanine. If you have a question that’s not on this list, send it to us at email@example.com and we will answer it for you.
There is no downside to theanine in terms of safety or side effects but there is a huge potential upside. Taking a single dose in the morning with a cup of coffee could be the key to starting off your work day relaxed, focused, and more productive.
Another study conducted in 2007 examined theanine’s effect on physiological and psychological stressors. The study gave participants either a theanine or placebo dose as the start of an examination or halfway through. The experiment used strict time constraints and mental arithmetic tasks as stressors. Subjects which received the theanine dose showed a reduction in heart rate and salivary immunoglubin when compared to the placebo group. 
1. Palva, S. and Palva, J.M., New vistas for a-frequency band oscillations, Trends Neurosci. (2007), doi:10.1016/j.tins.2007.02.001
3. Yokogoshi H, Kobayashi M, Mochizuki M, Terashima T (1998). “Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats”. Neurochem Res 23 (5): 667–73. doi:10.1023/A:1022490806093. PMID 9566605.
4. “FDA confirms GRAS status of Suntheanine”. NutraIngredients-USA.com. March 22, 2007. http://www.nutraingredients-usa.com/Industry/FDA-confirms-GRAS-status-of-Suntheanine.
6. Gomez-Ramirez M; Higgins, BA; Rycroft, JA; Owen, GN; Mahoney, J; Shpaner, M; Foxe, JJ (2007). “The Deployment of Intersensory Selective Attention: A High-density Electrical Mapping Study of the Effects of Theanine”. Clin Neuropharmacol 30 (1): 25–38. doi:10.1097/01.WNF.0000240940.13876.17. PMID 17272967.
8. Haskell CF, Kennedy DO, Milne AL, Wesnes KA, Scholey AB (2008). “The effects of l-theanine, caffeine and their combination on cognition and mood”. Biol Psychol 77 (2): 113–22. doi:10.1016/j.biopsycho.2007.09.008. PMID 18006208.
9. http://www.sciencenews.org/view/generic/id/8965/title/Distracted%3F_Tea_might_help_your_focus ” John J. Foxe of the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, N.Y
10. Nathan P, Lu K, Gray M, Oliver C (2006). “The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent”. J Herb Pharmacother 6 (2): 21–30. doi:10.1300/J157v06n02_02. PMID 17182482.
13. Roan, Shari (May 17, 2009). “L-theanine: New drinks promise focus, but more research attention needed”. Chicago Tribune. http://www.chicagotribune.com/features/lifestyle/chi-tc-health-theanine-0513may17,0,2196283.story.
14. Egashira N, Ishigami N, Pu F, et al., L-Theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder: an 8-week, randomized, double-blind, placebo-controlled, 2-center study, J Clin Psychiatry 2010;71:1-9., Stanley Research, http://www.stanleyresearch.org/Trial/Drug/awardedtrialdetail.aspx?id=252