caffeine

kafein

A stimulant compound found in coffee, tea, and other beverages that increases alertness.

• Coffee contains high levels of caffeine.
• Too much caffeine can make you jittery.
• She avoids caffeine after noon.
• Pharmacological studies demonstrate that caffeine blocks adenosine receptors in the brain, thereby reducing drowsiness and temporarily enhancing cognitive performance.
• Athletes sometimes consume caffeine before competitions to improve endurance, though regulatory bodies have established maximum permissible concentrations in blood samples.
• Sleep researchers advise avoiding caffeine consumption at least six hours before bedtime, as its half-life can significantly disrupt normal circadian rhythms.