Unlocking the Relaxing Brain Benefits of L-Theanine (Day or Night)
L-theanine is considered a non-essential amino acid. Unlike essential amino acids, it’s not directly involved in protein synthesis and energy production. Many people get a dose of L-theanine from drinking green tea and eating some mushrooms, along with added benefits for stress and sleep.
Amino acids are primarily known for being the building blocks of proteins, which the body needs to build muscles, grow hair and skin, strengthen bones, repair tissues, and fuel cellular processes, such as oxidation, digestion, and hormonal development.
There are two “official” types of amino acids, and one “unofficial” type:
- Essential: Consists of nine amino acids that must come from your diet as the body doesn’t naturally produce them.
- Non-essential: Includes 11 amino acids capable of being synthesized in the body, regardless of diet. They’re a part of the protein synthesis process—meaning they’re not totally “non-essential”1—but you can still make them if they’re not in your diet (for example: glutamine and glutamic acid, two compounds that are structurally similar to L-theanine).
- Conditionally essential: Some situations cause an imbalance between essential and non-essential amino acid synthesis. During periods of growth, pregnancy, illness, or recovery, you may need to supplement with one or more amino acids from each category to offset potential nutrient deficiencies from these physical states.2
This article spotlights the benefits of L-theanine, including plant sources and dosage recommendations. Keep reading to learn smart ways to minimize stress that make you feel better mentally and physically.
In this article
The Link Between Amino Acids and Brain Health
Although amino acids boast a number of physical benefits for muscle and bone health, they also influence brain function, namely as precursors to neurotransmitters.3 These chemical messengers mediate responses between neurons, controlling basic things like movement, thinking, and memory.
Neurotransmitters and L-theanine: A 2019 study in animals reveals a synergistic effect between the inhibitory neurotransmitter GABA and the amino acid L-theanine. The findings suggest that the relaxing effects of GABA are stronger when combined with L-theanine than they are on their own.
Scientists theorize that L-theanine affects a blocking action on the excitatory neurotransmitter glutamate.4
Neurotransmitters have a mutually dependent effect on each other. Too much5 and too little6 glutamate has been associated with elevated pain and anxiety, so the ability of L-theanine to increase the production of relaxing neurotransmitters, like serotonin, dopamine, and GABA, may explain L-theanine’s neuroprotective effects.7
Simply put, studies in animals reveal that L-theanine may help neurotransmitters strike a balance, providing a favorable chemical environment for better mental health.
Why Do People Use L-Theanine Supplements?
Now that you have a better understanding of how amino acids work, take a look at the (potential) benefits of L-theanine:
- Stress reduction: A small 2017 clinical study8 in healthy adults assessed the benefits of supplementing with 200mg of L-theanine a day. After four weeks, the study participants reported lower stress and depression and higher cognitive ability compared to the placebo group. Sleep quality also improved, but the researchers highlight few comparative differences between the study and placebo groups. Similar studies have also suggested that L-theanine reduces blood pressure spikes from stressful mental tasks.9
- Increased mental focus: Older research from the early 2000s10 found a strong correlation between L-theanine supplements, increased alpha brain waves, and subsequent relaxation. The findings, which continue to influence newer research, suggest that L-theanine boosts mental alertness.
- Improved sleep: A study published in Frontiers11 explains the modulatory effect of L-theanine on neurotransmitters in mice. Supplementing with L-theanine may make it easier to fall asleep and stay asleep based on its relaxing effect on EGG brain patterns. The researchers also found that L-theanine reverses the effects of caffeine in the brain.
- Weight loss: While there isn’t enough research to say that L-theanine supplements cause weight loss, drinking tea is associated with lifestyle perks12 such as stress management, hydration, and better sleep. All of these things promote mindful living, and as a result, can support a healthy BMI.
- L-theanine and caffeine for ADHD: A small 2020 study in boys13 found a positive correlation between a dose of L-theanine with caffeine for ADHD symptoms. These ingredients are naturally found in tea, and adults and children seem to tolerate low to moderate doses well. If you want a non-pharmaceutical option for attention and impulse control, tea is a fantastic option to try.
Types, Dosage, and Natural Sources
Green tea (Camellia sinensis) contains L-theanine, caffeine, and antioxidants—three ingredients that make tea a healthy alternative to coffee. Other teas in the Camellia sinensis family (white, oolong, black14) have similar therapeutic properties. Certain mushrooms, such as bay bolete15, contain L-theanine.
L-theanine, like most supplements, isn’t regulated by the FDA. Research studies involving 200-400mg of L-theanine daily haven’t reported significant side effects.16
Tip: People who are pregnant, preparing for or healing from surgery, or undergoing chemotherapy should consult with their healthcare provider about using L-theanine.
If drinking tea every day doesn’t sound like you, other supplements, like Purpose+ and Dream+, feature a dose of 200mg L-Theanine along with a blend of adaptogens. Supplements that combine the science of Western medicine with the wisdom of Eastern herbs give you an advantage over store-bought formulations that only come with L-theanine.
Plant medicine has also been known to have a synergistic effect.17 If your health goals involve stress management, better sleep, or sustainable energy and focus, you stand to benefit from plant-forward supplements (here at Sovereignty).
As one of 11 types of non-essential acids, L-theanine plays a role in many important body processes. It specifically aids in relaxation and focus, which in turn may improve stress levels and sleep quality. Research also highlights the importance of L-theanine for its neuroprotective effects.
During the day, try drinking tea with L-theanine and caffeine for a gentle morning/afternoon boost. Too much caffeine can affect your ability to fall asleep, so be mindful of how late you drink tea and how many cups you drink. Feel free to switch to caffeine-free versions later in the evening to get the most out of L-theanine.