caffeine + l-theanine

Caffeine + L-theanine is a combination of two naturally occurring compounds commonly found together in tea leaves. Caffeine is a central nervous system stimulant that increases alertness and energy by antagonizing adenosine receptors in the brain. L-theanine is an amino acid that promotes relaxation without sedation by modulating neurotransmitter activity—specifically increasing dopamine and reducing serotonin, noradrenaline, GABA release, and acting as a glutamate inhibitor. When combined in supplemental form (often at ratios such as 1:2 or 1:1), this stack provides synergistic effects on cognitive performance—improving attention-switching speed and accuracy, reaction time, sustained focus, mood balance, and reducing susceptibility to distraction compared to either compound alone. The combination also helps mitigate the jitteriness or anxiety sometimes associated with caffeine use while maintaining its benefits for mental clarity and wakefulness[1][3][5]. This blend is widely used as a nootropic supplement for work productivity enhancement, studying support, gaming focus improvement, fitness performance boost (especially during tasks requiring sustained attention), or as an alternative to coffee/energy drinks[6][8].

Brand names

ELITE FOCUSSmart CaffeineTheanineUP

Other names

caffeine & l-theanineL-theanine and caffeine combinationnootropic stack (caffeine + l-theanine)