What are the benefits of L-theanine (gamma-glutamylethylamide)?

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Last updated: May 27, 2025View editorial policy

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From the Research

L-theanine may have potential benefits for relaxation, stress reduction, and sleep quality, but the current evidence is limited and more research is needed to fully understand its effects. The most recent study, published in 2025, suggests that l-theanine can increase alpha waves in the brain associated with relaxation and selective attention, reduce stress and anxiety, and improve sleep quality, though findings are often inconsistent 1.

Potential Benefits of L-theanine

  • May promote relaxation without causing drowsiness by increasing alpha brain wave activity and influencing neurotransmitters like GABA
  • Can reduce anxiety and stress, with typical dosages ranging from 100-400mg daily
  • May improve focus and attention, particularly when combined with caffeine
  • Can support better sleep quality when taken before bedtime, typically 200mg 30-60 minutes before sleep

Important Considerations

  • The evidence supporting many health claims remains limited, especially the lack of rigorous human clinical trials
  • Caution is warranted regarding the purported health benefits, until stronger scientific substantiation emerges
  • L-theanine exhibits a good safety profile based on toxicology studies, but more research is needed to fully understand its effects

Recommended Usage

  • Take l-theanine on an empty stomach, as food may delay absorption
  • Start with a low dose, such as 100-200mg, and adjust as needed
  • Consider combining l-theanine with other sleep-promoting nutrients, such as melatonin or magnesium, for enhanced benefits 2

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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