Key Takeaways
- The global L-theanine market was valued at $6.25 billion in 2025 and is expected to reach $10.86 billion by 2033.
- L-theanine is an amino acid that helps promote relaxing alpha wave activity in the brain.
- L-theanine reduces some physiological indicators of stress within 15 minutes.
- L-theanine is often used in nootropic, sleep, occasional stress support, and gaming supplement formulations.
L-theanine is a neurologically active amino acid commonly used in dietary supplements for stress support and stress-related anxiety. 1Juneja LR, Chu D-C, Okubo T, Nagato Y, Yokogoshi H. L-theanine—a unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Tech. 1999;10:199-204
For brands researching what is L-theanine, its growing popularity is clear. The global L-theanine market was valued at $6.25 billion in 2025 and is expected to reach $10.86 billion by 2033, growing at a compounded annual growth rate (CAGR) of 7.14%. 2ReseearchSpark. Why the Theanine Market Is Becoming a Key Industry Focus. January 2026. Retrieved January 27, 2026 from https://www.linkedin.com/pulse/why-theanine-market-becoming-key-industry-focus-researchspark-rhnjc/. This growth is being driven by rising demand across industrial, commercial, and technology-enabled applications, supported by ongoing innovation, expanding use cases, and increased investment across key end-use industries worldwide.
In this blog article, we’ll explain what L-theanine is, how it works, and how it fits into today’s most popular supplement formulations, so you can make more confident formulation decisions and bring a differentiated, market-ready product to your customers.
What is L-Theanine and How Does it Work?
L-theanine is widely used for relaxation support, and for brand owners exploring what L-theanine is used for, its traditional connection to tea is a helpful starting point. Many Asian cultures have long consumed tea for its calming effects, which are due in part to the natural presence of L-theanine. While tea is often thought of as having less caffeine than coffee, L-theanine may help soften caffeine’s stimulant impact on the nervous system.
In the brain, L-theanine has been shown to increase serotonin and dopamine production, 3L-Theanine monograph. Alternative Medicine Review 2005;10(2):136-8. and it may also influence GABA. 4Lu K, Gray MA, Oliver C, et al. The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum Psychopharmacol Clin Exp 2004;19:457–65. Evidence from human EEG studies suggests L-theanine can significantly increase brain activity in the alpha frequency band, which is associated with a relaxed mental state without drowsiness. Alpha activity also plays a role in attention, which may help explain why research suggests L-theanine can support mental alertness while promoting relaxation. 5Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pac J Clin Nutr 2008;17 Suppl 1:167-8.
The Role of L-Theanine in Multi-Ingredient Formulations
For brands evaluating the health benefits of L-theanine, one of its most common applications is stress support. Research 6Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol 2007;74(1):39-45 suggests L-theanine supplementation may help reduce certain physiological indicators of stress within as little as 15 minutes and may have a beneficial effect on heart rate variability. Other studies 7Unno K, Tanida N, Ishii N, et al. Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary α-amylase activity, trait anxiety and subjective stress. Pharmacol Biochem Behav. 2013 Oct;111:128-35. have also demonstrated improvements in stress response with L-theanine supplementation.
In addition to its use as a standalone ingredient, L-theanine is also a popular choice in multi-ingredient formulations.
The Role and Benefits of L-Theanine in Popular Supplement Formulations
Many dietary supplement brands choose to include L-theanine alongside other nutraceutical ingredients, and this approach often makes strategic sense. First, L-theanine is an experiential ingredient that many consumers report feeling when they use it. Second, when paired with complementary ingredients, it can support a more well-rounded formula designed around specific wellness goals.
Based on our 45-plus years of contract development and manufacturing experience, we have seen the strongest-performing L-theanine formulations used in nootropic, sleep support, stress support, and gaming-focused supplements.
Nootropic Supplement Formulations
Several nutraceutical ingredients have been studied in combination with L-theanine and shown to deliver meaningful cognitive and stress-related benefits. In other cases, specific combinations have not been clinically evaluated as a finished formula, but the ingredients are commonly paired based on complementary mechanisms and consumer experience.
| Nootropic Combination | Benefit | How It Enhances Cognitive Performance |
| L-theanine + Caffeine | Boosts focus, alertness, and cognitive speed | L-theanine with caffeine helps improve focus while filtering out other stimuli. 8Kelly SP, Gomez-Ramirez M, Montesi JL, Foxe JJ. L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. J Nutr. 2008 Aug;138(8):1572S-1577S. 9Foxe JJ, Morie KP, Laud PJ, Rowson MJ, de Bruin EA, Kelly SP. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task. Neuropharmacology. 2012 Jun;62(7):2320-7. 10Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008 Aug;11(4):193-8. 11Giesbrecht T, Rycroft JA, Rowson MJ, De Bruin EA. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutr Neurosci. 2010 Dec;13(6):283-90. 12De Bruin EA, Rowson MJ, Van Buren L, Rycroft JA, Owen GN. Black tea improves attention and self-reported alertness. Appetite. 2011 Apr;56(2):235-40. It also helps speed and accuracy of cognitive performance and improves mental alertness. 13Owen GN, Parnell H, De Bruin EA, Rycroft JA. The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutr Neurosci. 2008 Aug;11(4):193-8. 14De Bruin EA, Rowson MJ, Van Buren L, Rycroft JA, Owen GN. Black tea improves attention and self-reported alertness. Appetite. 2011 Apr;56(2):235-40. |
| L-theanine + Rhodiola rosea + Magnesium + B Vitamins | Reduces stress during moodiness | L-theanine with Rhodiola was shown to reduce stress scores during moodiness 15Noah L, Morel V, Bertin C, et al. Effect of a combination of magnesium, B vitamins, Rhodiola, and green tea (L-theanine) on chronically stressed healthy individuals—A randomized, placebo-controlled study. Nutrients. 2022;14(9):1863. doi:10.3390/nu14091863., and modulate stress-related brain activity. 16Pickering G, Noah L, Pereira B, Goubayon J, Leray V, Touron A, Macian N, Bernard L, Dualé C, Roux V, Chassain C. Assessing brain function in stressed healthy individuals following the use of a combination of green tea, Rhodiola, magnesium, and B vitamins: an fMRI study. Front Nutr. 2023 Aug 16;10:1211321. doi: 10.3389/fnut.2023.1211321. PMID: 37662591; PMCID: PMC10469327. |
| L-theanine + Bacopa Monnieri + Saffron + Copper, folate, and B-/D-group vitamins | Improves cognitive function and stress | This combination improved cognitive function, stress scores, and mood scores using scientifically validated questionnaires. 17Cicero AF, Bove M, Colletti A, Rizzo M, Fogacci F, Giovannini M, Borghi C. Short-Term Impact of a Combined Nutraceutical on Cognitive Function, Perceived Stress and Depression in Young Elderly with Cognitive Impairment: A Pilot, Double-Blind, Randomized Clinical Trial. J Prev Alzheimers Dis. 2017;4(1):12-15. doi: 10.14283/jpad.2016.10. PMID: 29188854. |
| L-theanine + Ginkgo Biloba | Supports memory and cognitive performance | Ginkgo boosts blood flow to the brain, promoting cognitive performance 18Rai GS, Shovlin C, Wesnes KA. A double-blind, placebo controlled study of Ginkgo biloba extract (‘tanakan’) in elderly outpatients with mild to moderate memory impairment. Curr Med Res Opin. 1991;12(6):350-5. doi: 10.1185/03007999109111504. PMID: 2044394., while L-theanine improves attention and working memory tasks in adults. 19Baba Y, Inagaki S, Nakagawa S, Kaneko T, Kobayashi M, Takihara T. Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study. J Med Food. 2021 Apr;24(4):333-341. doi: 10.1089/jmf.2020.4803. Epub 2021 Mar 22. PMID: 33751906; PMCID: PMC8080935. |
| L-theanine + Lion’s Mane | Supports cognitive function, reduces moodiness | Lion’s Mane promoted cognitive function 20Saitsu Y, Nishide A, Kikushima K, Shimizu K, Ohnuki K. Improvement of cognitive functions by oral intake of Hericium erinaceus. Biomed Res. 2019;40(4):125-131. 21Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res. 2009 Mar;23(3):367-72. and reduced moodiness22Nagano M, Shimizu K, Kondo R, Hayashi C, Sato D, Kitagawa K, Ohnuki K. Reduction of depression and anxiety by 4 weeks Hericium erinaceus intake. Biomed Res. 2010 Aug;31(4):231-7., and L-theanine enhanced some cognitive functions. 23Kunugi H, Hidese S, Ogawa S, Ota M, Yasukawa Z, Ozeki M. Effects of Chronic L-theanine on Stress-related Symptoms and Cognitive Function in a Non-clinical Population: A Randomized Controlled Trial (P06-106-19). Curr Dev Nutr. 2019 Jun 13;3(Suppl 1):nzz031.P06-106-19. doi: 10.1093/cdn/nzz031.P06-106-19. PMCID: PMC6576271. |
Sleep Aid Formulation
Some nutraceutical ingredients have been studied in combination with L-theanine and shown to support key sleep parameters. In other cases, specific combinations have not been clinically studied as a finished formula, but the ingredients are commonly paired based on complementary benefits and consumer experience.
| Benefit | How It Supports Sleep Quality | |
| L-theanine + Melatonin | Promote overall sleep experience | Melatonin has been shown to be more effective for falling asleep faster, while L-theanine has been shown to be more effective for improved sleep. 24Kurdi MS, Athira AS, Ladhad DA, et al. Comparison Between Efficacy of Oral Melatonin (3 mg) and Oral L-theanine (200 mg) in Improving Sleep in Cancer Patients Suffering From Insomnia: A Randomised Double-Blinded Placebo-Controlled Study. Indian J Palliat Care. 2024;30(2):176-181. Used together, there is a complementary effect for overall sleep experience. |
| L-theanine + Valerian + Lemon Balm + Saffron | Reduces anxiety and promotes relaxation | Use of the Pittsburgh Sleep Quality Index showed that this combination helped to reduce time awake after sleep onset. 25Gutiérrez-Romero SA, Torres-Narváez ES, Zamora-Gómez AC, Castillo-Castillo S, Latorre-Velásquez AL, Betancourt-Villamizar C, Mendivil CO. Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial. Sci Rep. 2024 Apr 5;14(1):8062. doi: 10.1038/s41598-024-58661-z. PMID: 38580720; PMCID: PMC10997602. |
| L-theanine + Magnesium (along with vitamins + Rhodiola) | Helped improve sleep-related daytime dysfunction | Scientifically validated questionnaires confirmed that this combination helped improve sleep-related daytime dysfunction and cold pain sensitivity. 26Noah L, Morel V, Bertin C, et al. Effect of a combination of magnesium, B vitamins, Rhodiola, and green tea (L-theanine) on chronically stressed healthy individuals—A randomized, placebo-controlled study. Nutrients. 2022;14(9):1863. doi:10.3390/nu14091863. |
Stress Relief Supplement Formulations
Several nutraceutical ingredients have been studied in combination with L-theanine and shown to support a healthy stress response. In other cases, specific combinations have not been clinically studied as a finished formula, but the ingredients are commonly paired based on complementary benefits and consumer experience.
| Stress Relief Supplement | Benefit | How It Supports Stress Relief |
| L-theanine + Ashwagandha | Reduce stress, promotes relaxation | L-theanine has been shown to increase EEG alpha wave activity associated with relaxation and reduce salivary cortisol. 27Evans M, McDonald AC, Xiong L, Crowley DC, Guthrie N. A Randomized, Triple-Blind, Placebo-Controlled, Crossover Study to Investigate the Efficacy of a Single Dose of AlphaWave® L-Theanine on Stress in a Healthy Adult Population. Neurol Ther. 2021 Dec;10(2):1061-1078. doi: 10.1007/s40120-021-00284-x. Epub 2021 Sep 25. PMID: 34562208; PMCID: PMC8475422. Ashwagandha extract has demonstrated benefits for stress and anxiety. 28Ashwagandha: Is it helpful for stress, anxiety, or sleep? National Institutes of Health, Office of Dietary Supplements. Updated May 2, 2025. Retrieved January 27, 2026 from https://ods.od.nih.gov/factsheets/Ashwagandha-HealthProfessional/. This suggests a complementary effect. |
| L-theanine + GABA | Enhances calmness and reduces anxiety | Research demonstrated that both L-theanine and GABA reduced anxiety while improving psychomotor and cognitive performance scores. 29Deshpande SS, Kurdi M, Baiju A, Athira AS, Sarasamma AG, Gangadharan AK. Comparison of the effects of two amino acids, Gamma-aminobutyric acid (GABA) and L-theanine, on sedation, anxiety, and cognition in preoperative surgical patients – A randomized controlled study. J Anaesthesiol Clin Pharmacol. 2025 Jan-Mar;41(1):112-118. doi: 10.4103/joacp.joacp_417_23. Epub 2024 May 8. PMID: 40026748; PMCID: PMC11867345. |
| L-theanine + Lemon Balm | Reduces stress and anxiety | Research 30Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol 2007;74(1):39-45 showed L-theanine reduced some physiological indicators of stress, while other research showed that Lemon balm has anxiety-reducing properties. 31Ghazizadeh J, Sadigh-Eteghad S, Marx W, Fakhari A, Hamedeyazdan S, Torbati M, Taheri-Tarighi S, Araj-Khodaei M, Mirghafourvand M. The effects of lemon balm (Melissa officinalis L.) on depression and anxiety in clinical trials: A systematic review and meta-analysis. Phytother Res. 2021 Dec;35(12):6690-6705. doi: 10.1002/ptr.7252. Epub 2021 Aug 27. PMID: 34449930. |
Gaming Supplement Combination
Several nutraceutical ingredients have been studied in combination with L-theanine and shown to support cognitive domains that are relevant to video gaming performance.
| Gaming Supplement Combination | Benefit | How It Enhances Gaming Performance |
| L-theanine + Taurine + Ltyrosine + AcetylLcarnitine + citicoline + AlphaGPC + Caffeine + Mango leaf extract + Huperzia extract | Supports reaction time and cognitive flexibility | This combination improved reaction time, processing speed, inhibitory control, spatial working memory, and cognitive flexibility in healthy young adult participants. 32Medrano M, Molina-Hidalgo C, Alcantara JMA, Ruiz JR, Jurado-Fasoli L. Acute Effect of a Dietary Multi-Ingredient Nootropic as a Cognitive Enhancer in Young Healthy Adults: A Randomized, Triple-Blinded, Placebo-Controlled, Crossover Trial. Front Nutr. 2022 May 12;9:858910. doi: 10.3389/fnut.2022.858910. PMID: 35634417; PMCID: PMC9133906. Cognitive domains are relevant to video gaming performance. |
| L-theanine + Ginseng | Enhances processing speed and working memory speed | L-theanine enhances selective visual attention and processing speed, 33Karunaratne UW, Dassanayake TL. Effect of L-theanine on selective attention in a traffic-related reaction task in sleep-deprived young adults: a double-blind placebo-controlled, crossover study. Nutr Neurosci. 2025 Apr;28(4):471-480. doi: 10.1080/1028415X.2024.2383080. Epub 2024 Jul 25. PMID: 39052627. which are core cognitive functions in gaming. Panax ginseng improved some measures of memory and working memory speed.34Scholey A, Ossoukhova A, Owen L, Ibarra A, Pipingas A, He K, Roller M, Stough C. Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study. Psychopharmacology (Berl). 2010 Oct;212(3):345-56. doi: 10.1007/s00213-010-1964-y. Epub 2010 Jul 31. PMID: 20676609; PMCID: PMC2952762. A combination may provide complementary benefits. |
Conclusion
This article explained what L-theanine is, how it works, and why it continues to be a popular ingredient in modern supplement formulations. From stress support and relaxation to nootropic and sleep-focused blends, L-theanine is often selected because it is both versatile and highly compatible with other nutraceutical ingredients.
For brand owners, the key is not simply choosing a trending ingredient but building a formula that is properly dosed, manufactured consistently, and positioned to meet consumer expectations in a competitive marketplace.
To create a high-quality L-theanine product that can stand out in today’s competitive nutraceutical market, it is important to partner with an experienced herbal supplements manufacturer that follows GMP requirements and maintains strong quality control systems. Many brand owners also prioritize domestic production, which is why searches like “best supplement manufacturer usa” are common when evaluating manufacturing partners.
For over 45 years, new and established dietary supplement businesses have trusted Vitaquest with all their contract supplement development and manufacturing needs. We develop and produce over 4,000 custom formulas for more than 500 brands and offer a wide range of dosage forms, including:
- Capsules
- Powders
- Tablets
- Chewable tablets
- Effervescent tablets
- Oral disintegrating tablets (ODTs)
- And more…
If you’re ready to custom manufacture a high-quality L-theanine formulation with Vitaquest, we’d love to speak with you. Call 800-526-9095 to connect with one of our knowledgeable production specialists or request a competitive nutraceutical manufacturing quote if you’ve already finalized your project requirements.
