L-Theanine

L-Theanine, a naturally occurring amino acid primarily found in tea, particularly green tea, was first discovered in 1949 and later isolated from gyokuro leaves in 1950. Constituting about 1–2% of the dry weight of green tea leaves, L-Theanine imparts a unique brothy or savory (umami) flavor to green tea infusions. While the European Food Safety Authority found insufficient evidence for a direct link between theanine consumption and cognitive function improvement, stress alleviation, normal sleep maintenance, or reduction of menstrual discomfort, emerging research suggests potential benefits. L-Theanine supplementation, whether extracted from tea or chemically synthesized, has shown promise in reducing stress and anxiety, preventing stress-induced blood pressure increases, and enhancing some aspects of cognitive function, including attention and memory. Additionally, there is evidence supporting its potential to improve sleep quality by promoting a relaxed state in the brain, although more research is needed, especially regarding its effects on individuals with chronic conditions.