Between work, school, and daily life, busy days demand sustained focus for hours on end. To keep going, many turn to coffee. But more and more people are looking for a more steady source of energy—without the initial rush followed by a crash. That’s where matcha comes in: a naturally caffeinated beverage that’s popular for helping you stay focused when you need to pay attention.

Why Matcha Is Associated with Sustained Attention

Matcha has a unique characteristic that sets it apart from other caffeinated beverages: it naturally combines caffeine with L-theanine, an amino acid (one of the building blocks of proteins) found in large quantities in tea leaves grown in the shade. This combination is at the heart of its reputation.

Caffeine helps maintain alertness; L-theanine, on the other hand, is being studied for its calming effect, which does not cause drowsiness. Together, these two compounds appear to promote what is known as “calm alertness”: a state of sustained attention, with less nervousness than is sometimes felt after drinking a strong cup of coffee.

At Milia Matcha, we work exclusively with the Okumidori cultivar, grown in Mie and shaded for three to four weeks before harvest, which promotes the accumulation of L-theanine in the leaves. This is what gives it its sweetness, umami, and low bitterness, and it’s also what makes it a popular companion for workdays. We explain this process in detail in our article on matcha shading.

© Milia Matcha

What Science Says

Several studies have examined the effects of the caffeine-L-theanine combination on attention. An important clarification: these studies focus on specific doses of each compound, taken separately, and not on a cup of matcha. Nevertheless, they help explain why this combination has generated so much interest.

• In 2010, a British research team tested the combination of 97 mg of L-theanine and 40 mg of caffeine in 44 young adults: the participants performed more accurately on a task requiring them to switch quickly between instructions, and reported feeling more alert and less tired than when given a placebo^[1].
  
  
• In 2008, researchers in New York demonstrated that 100 mg of L-theanine and 50 mg of caffeine improved performance on a visual attention task, with brain activity (measured by electrodes) consistent with a more focused state of attention. L-theanine alone did not produce a measurable effect: it is indeed the combination that matters^[2].
  
  
• That same year, another study compared 50 mg of caffeine alone with 50 mg of caffeine combined with 100 mg of L-theanine: with the combination, participants were faster and more accurate, and less susceptible to distractions during a memory task^[3].
  
  

These studies point to the same conclusion: the combination of caffeine and L-theanine appears to promote more stable attention and better performance than caffeine alone. One point of clarification, however: the doses tested (approximately 100 mg of L-theanine) are equivalent to several cups of matcha, with a 2-gram serving typically providing 20 to 45 mg^[4]. Matcha is not an L-theanine “supplement,” but it remains the only common beverage that naturally combines the two molecules in proportions not found in either coffee or energy drinks.

When should you drink matcha to stay alert?

Matcha is best enjoyed when your attention is most needed. Many people enjoy their first cup in the morning to kick off the day; others have it in the early afternoon to get through the post-lunch slump without feeling jittery.

Work, studying, exam prep, or a long creative session: Matcha easily fits into the daily routine of students and working people alike, whether at the office or at home. If you’re sensitive to caffeine, just avoid drinking it too late in the day.

Making matcha a lasting ritual

A routine only works if it’s easy to stick to, even during busy weeks. That’s why we offer a flexible subscription: you choose your flavor and delivery frequency (every 1, 2, or 3 months), you get 10% off each delivery, and you can change, pause, or cancel your subscription from your customer account. For our most loyal customers, our 6- and 12-month prepaid packages offer up to 20% off with free shipping.

© Milia Matcha

Conclusion

Beyond its preparation—whisking the matcha and then taking a few minutes to savor it—is also a way to slow down before tackling the day. Perhaps that’s where its true power lies: not in what it offers in the moment, but in the sense of routine it establishes. A simple ritual, repeated every morning or early afternoon, that anchors your attention in a calm routine rather than in a sense of urgency.

Sources

^[1] Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience, 13(6), 283–290. https://doi.org/10.1179/147683010X12611460764840

^[2] Kelly, S. P., Gomez-Ramirez, M., Montesi, J. L., & Foxe, J. J. (2008). L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. The Journal of Nutrition, 138(8), 1572S–1577S. https://doi.org/10.1093/jn/138.8.1572S

^[3] Owen, G. N., Parnell, H., De Bruin, E. A., & Rycroft, J. A. (2008). The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutritional Neuroscience, 11(4), 193–198. https://doi.org/10.1179/147683008X301513

^[4] Kochman, J., Jakubczyk, K., Antoniewicz, J., Mruk, H., & Janda, K. (2021). Health benefits and chemical composition of matcha green tea: a review. Molecules, 26(1), 85. https://doi.org/10.3390/molecules26010085

^[5] EFSA (2015). Scientific Opinion on the Safety of Caffeine. EFSA Journal, 13(5), 4102. https://doi.org/10.2903/j.efsa.2015.4102