Caffeine pills stimulate the CNS and temporarily rids the mind of feelings of tiredness.* Some of the most common products containing caffeine are sports drinks, energy drinks, tea, coffee, chocolate, anything containing guarana, and most soft drinks. It provide an almost instantaneous increase to general alertness and are useful in many situations in which one may need to temporarily give their own energy levels a quick boost.* Of course, cognitive functions still need real sleep to be fully restored, so caffeine pills should not be used as a substitute for a good night's sleep.* This is the gelatin capsule form. <b>This supplement contains pure caffeine and should be used with caution.</b>