Mon-Fri 7am to 4:30pm (MST)   800-357-5027 or 520-748-0388
how does l-theanine affect your mood?

How Does L-Theanine Affect Your Mood?


February 22, 2021 | Published by

Like SAMe and GABA, l-theanine is a naturally-occurring amino acid. Results of animal- and human-based research support that regular intake of l-theanine improves mental performance, attention and quality of sleep. But how exactly does l-theanine work, and how does it affect your mood?

How Does L-Theanine Work?

L-theanine increases levels of GABA, serotonin, dopamine and other brain-calming chemicals. These neurotransmitters work in the brain to regulate mood, emotions, alertness, concentration, sleep, and even appetite, energy and other cognitive skills. Thus, an increase in these chemicals promotes relaxation and can help increase quality of sleep.3

In addition to boosting levels of “feel-good” chemicals, l-theanine also lowers the levels of excitatory brain chemicals. These are chemicals associated with stress and anxiety. This process may also help protect brain cells against stress and age-related damage. 3

Wakeful relaxation is the feeling you get when meditating, daydreaming, or engaging in creative activities. This feeling is powered by alpha brain waves, which l-theanine can help enhance. These waves are also present during REM sleep. Alpha waves support relaxation, focus and creativity. 3

Benefits of L-Theanine

Better Sleep

Since l-theanine helps to increase relaxation and reduce stress, it can help improve sleep in different ways. It may help you fall asleep quicker and easier at bedtime, thanks to the boost to relaxation. There is research that shows l-theanine can also improve the quality of sleep by the same relaxation properties, as well as its ability to reduce anxiety. 3

Reducing Stress and Anxiety

L-theanine has anxiolytic properties, meaning it works to help reduce anxiety. Some anxiolytics, like hops and valerian, can make people feel drowsy or sleepy. One great thing about l-theanine is that it promotes relaxation and reduced stress without sedative effects. This amino acid has positive effects on both mental and physical effects of stress, including lowering heart rate and blood pressure.3

A study in 2019 examined the effects of l-theanine on stress-related symptoms and cognitive functions in healthy adults. The results showed that after 4 weeks of l-theanine use, stress-related symptoms (depression, anxiety, sleep difficulty) decreased and cognitive function (verbal fluency and executive function) improved. 2

Enhanced Attention, Focus and Memory

When you’re experiencing stress, your body increases the release of certain hormones, namely cortisol and corticosterone. These increases help your body respond to stress but inhibit other types of brain activity, like memory formation and spatial learning. L-theanine helps to lower the levels of corticosterone, which helps avoid the reduction in memory and learning capacity. 3

L-theanine may also help boost other mental skills. Research shows that l-theanine can help increase attention span and reaction time in people who are prone to anxiety. Another study shows that taking l-theanine helped reduce the amount of errors made in a test of attention. 3

In addition to the established stress- and anxiety-reducing benefits of l-theanine, emerging research findings show that this naturally occurring amino acid has many important beneficial effects on health and brain function including reduced risk of cardiovascular disease and reduced obesity. 1


  1. Lake, J. L-Theanine for Different Mental Health Problems. Psychology Today.
  2. Hidese, S, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. NCBI.
  3. Breus, M. What You Need to Know About L-Theanine. Psychology Today.

Tags: , , , , ,

Categorised in:

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.