L-Theanine and Suntheanine are two closely related nootropics that are often compared for their benefits and side effects.
Suntheanine is a derivative of L-Theanine, promoted as being a purer, more concentrated form and requiring a smaller dosage.
Taiyo International Inc., the maker of Suntheanine, says that Suntheanine uses a better fermentation process that leads to a higher quality product, but many are left to wonder if there is any difference.
Are there any real distinctions between natural L-Theanine vs Suntheanine branded supplements? Here’s use and benefit information on both compounds, with information from user reviews on which product people choose and why.



- Supports focus, attention & mood
- Helps to reduce stress & anxiety
- Neuroprotective & increases NGF
L-Theanine – Uses and Benefits
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L-Theanine is a naturally-occurring amino acid derived from the leaves of green tea.
It is classified as an anxiolytic compound, meaning it is psychoactive and capable of crossing the blood-brain barrier and reducing the symptoms of anxiety.
It does this largely by stimulating neurochemicals which limit the nervous system’s over-firing responses. One of the neurotransmitters L-Theanine is known to stimulate is GABA, an amino acid which regulates metabolism and the transmission of stress messages.
L-Theanine also stimulates the synthesis of Dopamine in the brain, and may increase Serotonin levels, both of which can contribute to de-stressing the mind, relaxing muscles, stimulating pleasure centers, and creating a feeling of tranquility.
For all of these reasons, L-Theanine has become a very popular supplement. It’s natural, has little to no side effects, and does not build tolerances or addictions.
L-Theanine is available as a dietary supplement only, and the FDA has not approved L-Theanine as a drug to prevent or treat any conditions.
What Is Suntheanine?
Suntheanine is essentially a proprietary branded form of L-Theanine produced by Taiyo International, Inc., a green tea manufacturer from Japan. The makers of Suntheanine claim that their product is a pure form of L-Theanine that has been separated from another compound found in green tea, D-Theanine.
Some claim that D-Theanine has a slightly inhibitory effect upon the absorption of L-Theanine by the body. However, there is no research to conclusively show this.
In green tea, D-Theanine is naturally found alongside L-Theanine with no adverse effects and many of the same reported benefits. Why would the makers of Suntheanine make such a big point about purifying their product of one of its base components? As we’ll see below, there appears to be no qualitative difference in the battle of L-Theanine vs Suntheanine.
L-Theanine vs Suntheanine – Efficacy
Is there a difference in the effects one feels when using L-Theanine vs Suntheanine? This is obviously the most important question for anyone wishing to explore the world of nootropics.
Chemically, they work the same way. Both are analogs to Glutamine which increase the production of GABA and generate alpha brain waves.
Users have weighed in and reported that there is no quantifiable difference in the subjective experience of taking one compound versus the other.
Both generate anti-stress effects, both stimulate focus and creativity, and both create feelings of relaxation and peacefulness. Neither product produces notable side effects or tolerances.
Of course, as with all supplements, individuals have unique needs for dosage based on their bodies, tolerances, and goals. But there generally seems to be no significant difference between generic L-Theanine and branded Suntheanine.
L-Theanine vs Suntheanine – Price Comparison
The biggest difference of L-Theanine vs Suntheanine is clearly price. With content and efficacy basically the same, we took a look at the price comparison of the two products and found Suntheanine to be significantly more expensive than L-Theanine.
A typical 50 gram bottle of Suntheanine powder generally sells for at least 30 percent more than a comparable bottle of L-Theanine. Especially for frequent or daily users of the supplement, this price difference can really add up.
As long as you are buying L-Theanine from a trusted source, there is little reason to spend the extra money on a brand name.
L-Theanine – The Best All-Around Pick For Anxiety Relief
For thousands of years, people enjoyed the benefits of L-Theanine in the form of green tea, without the need for a middle-man to brand the compounds within it. Today, the modern user must balance benefits, efficacy, and of course, price, when choosing supplements, especially for daily use.
Nootropics can be effective for reducing anxious thoughts and stress, along with a host of other cognitive benefits. While the Suntheanine brand does have greater name recognition, most users are able to derive the same benefits by taking generic L-Theanine at a lower cost.
- Jiang W, Gao M, Sun S, Bi A, Xin Y, Han X, Wang L, Yin Z, Luo L. Protective effect of L-theanine on carbon tetrachloride-induced acute liver injury in mice. Biochem Biophys Res Commun. 2012
- Scheid L, Ellinger S, Alteheld B, Herholz H, Ellinger J, Henn T, Helfrich HP, Stehle P. Kinetics of L-theanine uptake and metabolism in healthy participants are comparable after ingestion of L-theanine via capsules and green tea. J Nutr. 2012
- Kim TI, Lee YK, Park SG, Choi IS, Ban JO, Park HK, Nam SY, Yun YW, Han SB, Oh KW, Hong JT. l-Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappaB pathways. Free Radic Biol Med. 2009
- Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pac J Clin Nutr. 2008
- Rao TP, Ozeki M, Juneja LR. In Search of a Safe Natural Sleep Aid. J Am Coll Nutr. 2015
- Bindal S, Gupta R. L-theanine synthesis using γ-glutamyl transpeptidase from Bacillus licheniformis ER-15. J Agric Food Chem. 2014
Article last updated on: March 18th, 2018 by Nootriment
5 Comments
Suntheanine is the only 99% pure, pharmaceutical grade L-theanine. It has over 40 US and international patents. There is no comparison to other kinds of L-theanine.
Moreover, if you simply buy L-theanine, you don’t know what you’re getting.
Lol what is this article. Suntheanine is just L-theanine. There’s no point in even mentioning D-theanine because L-theanine has no D-theanine in it either. It would be just be called “theanine” if it had both.
“Moreover, if you simply buy L-theanine, you don’t know what you’re getting.” I mean if your vendor is lying about what they have, they could just as well be lying about selling a brand-name version of L-theanine. Just go with any decently respectable brand (Now Foods, Nootropics Depot, Jarrow, BulkSupplements to name a few) and you’ll be fine.
have you boughten L-theanine before? if so tell me which brand to buy because im lost af. leave a link if you can thanks.
Will expect the manufactures to lay their cards on the table–san all the jingoisms.
Sure they have scientists to validate their claims.
I dont any of them to come clean on this.
AGC
THE REAL QUESTION IS WHICH IS MORE BIOAVAILABLE, NOT WHAT THE DIFFERENCE IS BETWEEN A BRAND NAME! IF L-THEANINE IS WATER SOLUBLE, WHICH IT IS, THEN IT MUST HAVE A LIPID OR OTHER CARRIER BOUND TO IT TO GET INTO THE LOWER INTESTINES FOR ADEQUATE ADSORPTION. TRY CAPS IN COLD PRESSED COCONUT OIL OR WITH LECITHIN. THIS IS TRUE WITH ALL HERBS, VITAMINS, ETC. WHICH ARE WATER SOLUBLE. SO, LOOK FOR L-THEANINE DERIVED FROM FRESH GREEN TEA LEAVES SHADE DRIED, AND PROCESSED WITH THE LEAST AMOUNT OF NON-TOXIC CHEMICALS. BETTER IS FRESH HIGH GRADE GREEN TEA WITH L-THEANINE EXTRACTED (GOLD STANDARD IS SUPERCRITICAL CO2 EXTRACTION) THEN CILD-PRESSED WITH ORGANIC,NON-GMO, UNREFINED,COLD PRESSED COCONUT OIL OR SAME EVOO. BEST WOULD BE MATCHA (CEREMONIAL GRADE) GREEN TEA- SCCO2 EXTRACTION L-THEANINE- WITH THE OIL/FAT (ORGANIC & ALL THE OTHER LISTED SPECS FOR TEA & OIL/FAT). YOU CAN DO SOME OF THIS YOURSELF FAIRLY EASILY WITH THE MATCHA AND FAT/OIL/LECITHIN USING GENTLE WARMING, STIRRING (OVER DOUBLE BOILER) AND COOLING TO PUT INTO 00 VEGGIE CAPS,REFRIGERATE,AND TAKE BY MOUTH.