L-Theanine Health Benefits – Sleep, Stress & Anxiety

L-Theanine Improves Sleep, Stress, Anxiety

L-Theanine Health Benefits – It’s Time To Relax

Increased stress and poor sleep is the price we pay to live in our modern, fast-paced world.

This is bringing increased attention to supplements that can help us feel balanced and better able to maintain our focus while keeping stress under control.

Found in Tea Leaves

L-theanine is an amino acid found most commonly in all types of tea, but especially green tea.

However, it’s also commonly available in supplement form. Since research suggests it can promote relaxation without making you drowsy, it’s an effective way to calm down any time of day (1). But that’s not all L-theanine is good for.

Let’s look at all the science-backed ways this amino acid can help enhance your health.

Powerful Anti-Stress Benefits

L-theanine’s anti-stress effect is due to how it blocks the excitation of cortical neurons (2).

It’s also easily able to cross the blood-brain barrier, and when taken by pill or capsule has been shown to increase concentrations of the amino acid for up to five hours in the brain (3)

The amygdala and hippocampus are two areas of the brain that control the fear response and manage memory.

Research suggests that L-theanine can significantly affect these parts of the brain, improving memory and reducing anxiety (4).

Induces a State of Wakeful Relaxation

Researchers have demonstrated that L-theanine can increase the alpha brain waves associated with ‘wakeful relaxation,’ by affecting attention, sensitivity to arousal, and mental alertness.

A recent study analyzed the effects of the amino acid on brain waves up to one and a half hours after test-subjects took a 50 milligram dose.

The findings indicated an increase in alpha wave activity across the time studied in the L-theanine group compared to those who only received a placebo.

The study authors believe this data suggest L-theanine, at this dose, can increase alpha wave activity in the brain to improve both attention and focus without acting as a stimulant (5).

L-Theanine May Improve Sleep

Researchers in another study using human participants find that daily supplementation with L-theanine can significantly improve sleep quality (6).

Other studies find that L-theanine can especially help improve sleep quality in people experiencing forms of hyperactivity, like ADHD. (7)

It can also help counter the effects of certain stimulants, like caffeine. So, if you drink lots of coffee or take other stimulants, the calming effect of L-theanine could help you slow down when you need to rest.

L-Theanine Protects Memory

A double-blind, placebo-controlled study conducted on patients with mild cognitive impairment (early dementia) found that a combination of green tea extract and 60 milligrams of L-theanine given three times every day for four months noticeably improved cognition and memory (8).

The scientists concluded that L-theanine also increased the brain’s theta wave production; theta waves are an indicator of increased awareness and cognition.

Works Well With Caffeine

When taken together with caffeine, L-theanine can help increase focus and attention.

Research published in 2013 discovered that moderate levels of L-theanine and caffeine helped young adult study participants to better focus while performing demanding tasks (9).

The participants also reported feeling generally more alert and less fatigued. Another study, found that this effects may be felt as fast as 30 minutes after L-theanine use (10).

L-Theanine is Good for Your Heart

Green tea is a great source of L-theanine, and numerous studies have found evidence that it helps reduce inflammation and supports heart health (11).

Some scientists think that green tea’s cardio-protective properties are mostly due to the L-theanine it contains rather than the other substances it contains like catechins and theaflavins (12).

L-theanine could even help prevent spikes in blood pressure from stressful events by regulating nitric oxide levels in the blood (13).

Nitric oxide is a chemical our bodies produce that helps cells communicate, dilates blood vessels to control blood, and decrease inflammation.

Studies find that giving patients L-theanine within 12 to 24 hours after a stroke could reduce the damage this event causes while protecting healthy brain cells (14).

The Alpha Wolf Difference

L-Theanine is crucial to supplement with in today’s fast paced, ultra stressed environments.

Both our Sandman sleep aid and our Next Level Superfoods Multivitamin feature 100mg of L-Theanine to help ensure you get the sleep, rest and recovery you need to be at 100% everyday!


  1. Anna C Nobre PhD, Anling Rao PhD, Gail N Owen PhD. L-theanine, a natural constituent in tea, and its effect on mental state. Unilever Food and Health Research Institute, Vlaardingen, The Netherlands 2 Department of Experimental Psychology, Oxford University, UK – Link
  2. Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007 Jan;74(1):39-45. Epub 2006 Aug 22 – Link
  3. Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. l-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr. 2016;59(2):93–99. doi:10.3164/jcbn.16-15 – Link
  4. Shen M, Yang Y, Wu Y, Zhang B, Wu H, Wang L, Tang H, Chen J. L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions. Phytother Res. 2019 Feb;33(2):412-421. doi: 10.1002/ptr.6237. Epub 2018 Nov 25 – Link
  5. 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;17 Suppl 1:167-8 – Link
  6. Jackson Williams, Jane Kellett, Paul Daniel Roach, et al. l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. Beverages 2016, 2(2), 13 – Link
  7. Barrett JR, Tracy DK, Giaroli G. To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and adolescents with attention-deficit/hyperactivity disorder. J Child Adolesc Psychopharmacol. 2013;23(10):640–647. doi:10.1089/cap.2013.0059 – Link
  8. Sang-Ki Park, In-Chul Jung, et al. 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. JOURNAL OF MEDICINAL FOOD J Med Food 14 (4) 2011, 334–343 # Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition – Link
  9. T. Giesbrecht, J.A. Rycroft, M.J. Rowson & E.A. De Bruin (2010) The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness, Nutritional Neuroscience, 13:6, 283-290 – Link
  10. https://www.liebertpub.com/doi/pdf/10.1089/10762800151125092
  11. Babu PV, Liu D. Green tea catechins and cardiovascular health: an update. Curr Med Chem. 2008;15(18):1840-50 – Link
  12. Chengjian Li, Qiongxian Yan, Shaoxun Tang,et al. L-Theanine Protects H9C2 Cells from Hydrogen Peroxide-Induced Apoptosis by Enhancing Antioxidant Capability. Med Sci Monit. 2018; 24: 2109–2118 – Link
  13. Yoto A, Motoki M, Murao S, Yokogoshi H. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol. 2012;31(1):28. Published 2012 Oct 29. doi:10.1186/1880-6805-31-28 – Link
  14. Zukhurova M1, Prosvirnina M, Daineko A, Simanenkova A, Petrishchev N, Sonin D, Galagudza M, Shamtsyan M, Juneja LR, Vlasov T. L-theanine administration results in neuroprotection and prevents glutamate receptor agonist-mediated injury in the rat model of cerebral ischemia-reperfusion. Phytother Res. 2013 Sep;27(9):1282-7. doi: 10.1002/ptr.4868. Epub 2012 Oct 24 – Link