Which is the most important stimulant in tea leaves?

The most important stimulant in tea leaves is caffeine. Caffeine acts as a central nervous system stimulant, providing a boost in alertness and reducing fatigue. In addition to caffeine, tea leaves also contain the amino acid L-theanine, which can promote relaxation and enhance focus, creating a balanced effect. Together, these compounds contribute to the unique stimulating and calming properties of tea.