The Takeaway: L-Theanine and L-Glutamine offer complementary daily support for your body's natural sense of calm and mental clarity, helping you stay present through the demands of a full day.†
Many of us know the feeling of being "wired but tired" — mentally exhausted yet unable to fully switch off at the end of a demanding day. Supporting the body's natural balance between mental alertness and calm recovery is an important part of daily wellness. Two amino acids found in your Functional Nature formula — L-Theanine and L-Glutamine — each play a distinct and complementary role in supporting that balance.
Think of it as a "Top-Down" and "Bottom-Up" approach. L-Theanine has been studied for its role in supporting the body's natural relaxation response and mental clarity, with some research exploring a potential connection to states of calm mental engagement. L-Glutamine, meanwhile, plays a foundational role in supporting the body's natural metabolic balance — and as we explored in our earlier posts on the Gut-Brain Axis, a well-supported gut environment contributes to overall daily wellness in ways that extend far beyond digestion. Together, these two amino acids offer complementary daily support for your body's natural sense of calm and mental clarity.†
The clinical research supporting L-Theanine continues to grow. A 2019 randomized controlled trial by Hidese et al., published in Nutrients, examined the effects of L-Theanine on healthy adults over four weeks and found that participants maintained healthy cognitive function and a balanced response to daily stressors.† More recently, a 2024 randomized, double-blind, placebo-controlled trial by Moulin et al., published in Neurology and Therapy, demonstrated that L-Theanine supplementation was safe and well-tolerated in healthy adults experiencing moderate everyday stress, with participants reporting meaningful support for their perceived stress levels over a 28-day period.† For the professional or parent navigating a full life, this combination offers thoughtful daily support for mental clarity and calm.†