L-Theanine: Calm Focus, the Caffeine Stack, and Anxiety Evidence
Key takeaways Best-supported use: pairing 100–200 mg L-theanine with caffeine (50–100 mg) to reduce jitter and improve sustained attention on cognitive tasks — multiple RCTs and one systematic review support the combination effect (Nutritional Neuroscience, Camfield 2014). For acute situational stress and anxiety, small RCTs (200–400 mg) show reductions in self-rated stress and salivary cortisol … Read more