title_body: How could you feel the caffeine effect most quickly?
upvoted_answer: If you want the effects of the caffeine to be felt the most quickly, you probably should buy caffeine powder or pills, be careful though that you could easily overdose yourself to death with the caffeine powder or if you took more pills than recommended.
  Though, if you don't want to buy the isolated caffeine, drinking it would probably be quicker, since otherwise you'd lose the effect of the absorption by the mouth (which is faster because it goes straight into the bloodstream), and you'd still have to digest the powder to get to the caffeine.