From work stresses to family strains and so much more, feelings of anxiety and chronic stress practically permeate our lives. Nearly one third of American adults will experience an anxiety disorder at some point during their lives¹. Many individuals have decided to turn toward natural remedies to help them manage these difficult feelings. One natural supplement that has gained attention in recent years is the amino acid L-theanine.
But what exactly is L-theanine and how does it work? Follow along with us as we delve into the origins of L-theanine and explore how it works in the body, its impact on mental health, and the potential ways you can incorporate L-theanine into your daily routine.
L-theanine is a bioactive compound found primarily in tea leaves, especially in green tea (Camellia sinensis). Japanese scientists first discovered the compound as a green tea constituent in 1949. Since then, it has been studied for its potential health benefits, which may include "antioxidant, anti-inflammatory, neuroprotective, anticancer, metabolic regulatory, cardiovascular protective, liver and kidney protective, immune regulatory, and anti-obesity effects²."
L-theanine is a non-protein amino acid, meaning it does not naturally occur in the human genetic code. However, it does appear in the polypeptide chains of fungi and some plants³.
One of the primary reasons why L-Theanine has gained popularity is its potential to reduce feelings of anxiety and the effects of the stress response. The mechanism behind its effects lies in how it interacts with the brain.
When consumed, L-theanine can cross the blood-brain barrier to exert its effects directly on the brain. Studies have indicated that these effects include increasing the production of alpha brain waves, which are associated with relaxed wakefulness⁴. In this more relaxed state, individuals may experience a reduction in anxiety symptoms and stress related symptoms without feeling drowsy as a result.
In addition to its alleviating effects on feelings of anxiety and stress, L-Theanine has been found to offer numerous other health benefits as well.
L-Theanine has been shown to improve sleep quality and reduce experiences of sleep disturbance by increasing relaxation and reducing anxiety before bedtime. Research demonstrates that L-theanine has the ability to increase the production of neurotransmitters like gamma-aminobutyric acid (GABA), an important animo acid in the central nervous system⁵.
This feat combined with its boosting of alpha brain wave activity makes L-theanine a safe natural sleep aid that promotes a sense of calmness, helping individuals fall asleep faster experience a more restful sleep.
L-theanine may also enhance cognitive function, particularly in the areas of focus, attention, and memory. The increased production of alpha brain waves could have some cognitive performance effects, but research suggests that L-theanine may also interact with BDNF, or brain derived neurotrophic factor⁶.
BDNF has various roles in the brain, including the regulation of neurotransmitters and changes in plasticity. Neuroplasticity changes coincide with learning and building memories. L-theanine's interaction with BDNF indicates that it may play a part in memory formation as well as positive mood regulation. Both of these cognitive functions are important for better focus and overall increased cognitive performance.
Combining L-theanine with caffeine (which is commonly found alongside the amino acid in tea) may boost these cognitive improvements by producing a state of relaxed alertness. Increased alpha brain wave activity may also contribute the creation of that state.
L-theanine may have immune-boosting properties as well. By modulating the immune response, L-Theanine can help strengthen the body's defense mechanisms and promote overall well-being. One study indicated that the amino acid may be particularly effective as an immune supplement to athletes who regularly endure strenuous physical exercise⁷.
It's also worth noting that physiological stress responses can have a negative impact on immune health. Since L-theanine may be able to produce an anti-stress effect for some individuals, this could provide a small boost to the immune system too by alleviating stress.
Let's explore a few of the most common ways to go about bringing L-theanine into your daily routine.
If you want the most natural form of L-theanine, you can consume this powerful amino acid by drinking tea. Green and black tea contain the highest amounts of L-theanine. You can also incorporate tea in different forms such as green tea extract.
The main dietary source of L-theanine is tea, but there are a few other foods that contain small amounts of the amino acid like certain types of mushrooms and legumes.
If tea isn't your ideal beverage, you can also try an L-theanine supplement. Human clinical trials suggest that L-theanine supplements for healthy adults could "promote mental health in the general population with stress-related ailments and cognitive impairments⁸."
When considering dosages for a mood or dietary supplement, you should follow the instructions of the manufacturer or a healthcare professional.
Although L-theanine supplements are typically safe for most healthy adults, take note that L-theanine can interact with certain medications, such as those prescribed for high blood pressure. Remember to speak with your healthcare provider before adding any form of supplements to your normal routine in order to avoid potential interactions.
L-theanine supports feelings of relaxation. Caffeine improves cognitive performance. When consumed together, L-theanine and caffeine may create a harmonious balance for some, as L-theanine can counteract the potential jitters or anxiety that caffeine alone may induce⁹. This combination may help individuals experience increased mental clarity and concentration without the usual drawbacks associated with high caffeine intake.
Keep in mind that caffeine may increase feelings of anxiety in some individuals, so exercise caution and discretion when it comes to your caffeine intake.
BioNeurix's Seredyn Complete Calm is an emotional supplement that helps to reduce feelings of anxiety, stress, and worry. Our carefully crafted formula contains only standardized plant extracts and amino acids that promote a calm, confident state of mind and optimize your brain's emotional pathways.
L-theanine produces a pronounced feeling of tranquility in as little as 15 minutes. Seredyn contains SunTheanine® brand L-theanine, the purest and most potent L-theanine available. Many other formulas sold as "L-theanine" actually contain green tea extract, not pure SunTheanine® brand L-theanine. As a result, these products provide only a small, ineffective dose of L-theanine.
Additionally, only Seredyn combines L-theanine with high-quality valerian and passion flower extracts to provide a complete anti-anxiety supplement.
L-theanine is a natural remedy that shows promise in alleviating feelings of anxiety and stress. Its ability to promote relaxation and calmness without causing drowsiness makes it an attractive option for individuals seeking a natural approach to managing their stress levels.
Remember that everyone's body is different, and what works for one person may not work for another, so you should consult with your healthcare professional before starting any new supplement.
(1) NIMH Information Resource Center (2023) Any Anxiety Disorder
(2) Li, Ming-Yue, et al (April 2022) L-Theanine: A Unique Functional Amino Acid in Tea (Camellia sinensis L.) With Multiple Health Benefits and Food Applications
(3) Ding, Yun, et al (September 2020) Impact of non-proteinogenic amino acids in the discovery and development of peptide therapeutics
(4) Nobre, Anna C, et al (2008) L-theanine, a natural constituent in tea, and its effect on mental state
(5) Dasdelen, Muhammed Furkan, et al (April 2022) A Novel Theanine Complex, Mg-L-Theanine Improves Sleep Quality via Regulating Brain Electrochemical Activity
(6) Miodownik, Chanoch, et al (August 2011) Serum levels of brain-derived neurotrophic factor and cortisol to sulfate of dehydroepiandrosterone molar ratio associated with clinical response to L-theanine as augmentation of antipsychotic therapy in schizophrenia and schizoaffective disorder patients
(7) Juszkiewicz, A, et al (February 2019) The effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exercise
(8) Hidese, Shinsuke, et al (October 2019) Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial