Isabel Viña, science communicator and physician: "L-theanine induces relaxation and helps us fall asleep."

Dr. Isabel Viña, known on social media for her ability to communicate health topics in a clear and accessible way, has published a video on TikTok explaining the benefits of L-theanine, a natural amino acid found in green tea. Her post, which lasted just a couple of minutes, has sparked great interest among users due to its direct focus on the positive impact of this substance on the nervous system.

“Today I'm here to tell you why L-theanine is an amino acid with relaxing properties,” Viña begins in her friendly style. This compound, she explains, is obtained through the natural fermentation of green tea, from which it is extracted, purified, and isolated for use in supplements. Unlike theine, another substance also present in tea, L-theanine has no stimulating effects, making it a safe option for those seeking tranquility without altering their alertness.

Isabel Viña emphasizes that one of L-theanine's most significant properties is its ability to modify brain activity, especially by facilitating the transition from beta brain waves, characteristic of states of wakefulness and attention, to alpha waves, which are associated with deep relaxation. "They allow us to enter that state of tranquility that then naturally allows us to fall asleep," she explains.

This effect has been supported by various studies, which link alpha waves with a relaxed yet conscious state of mind, ideal for practices such as meditation or sleep preparation. Thus, L-theanine has positioned itself as a natural alternative to other more aggressive treatments for occasional insomnia or daily stress.

In addition to its effect on brain waves, the doctor emphasizes that L-theanine modulates various key neurotransmitters involved in emotional balance. According to her, this substance positively affects dopamine and serotonin, known for their role in regulating mood, and also GABA, the main inhibitory neurotransmitter in the central nervous system.

“GABA is the neurotransmitter that many drugs like benzodiazepines act on, and that's why they relax,” Viña recalls, making L-theanine a less invasive option with similar, albeit milder, effects. She also points out that it blocks glutamate receptors, an excitatory neurotransmitter that, when overactivated, can cause nervousness and difficulty sleeping.

Another striking aspect mentioned by the doctor is the impact of L-theanine on the rhythm of cortisol, the stress hormone. "It modulates and restores the normal cortisol rhythm," she indicates, which has led to the suggestion that it could be a potential adaptogenic compound, that is, a substance that helps the body adapt to stress and maintain internal balance.