How quickly are the effects of caffeine felt by the brain?

by Peter lam
(Hong Kong)

QUESTION:

Approximately how long does it take for the caffeine in coffee to have an effect?


ANSWER:

My assumption has always been that the absorption of caffeine into the system is quite fast. I guess I imagine my first few sips of coffee in the morning, and see myself saying “Ahhh...” as if the caffeine were hitting my brain cells in just a couple of seconds.

But this doesn’t appear to be the case at all. I had to do some research to find the answer, but here it is: When you drink a cup of coffee it takes anywhere from 45 to 90 minutes for most of the caffeine to get to your brain.

This is according to the Walter Reed Army Institute of Research in Washington. The US Army became interested in caffeine because it often has to find ways to keep its soldiers awake and alert.

The reason why caffeine takes so long to have an effect is that it is absorbed by the stomach and intestinal lining, and then makes its way to the brain through the bloodstream.

The army found that caffeinated chewing gum worked better for their purposes, because the caffeine was absorbed by the tissues of the mouth and was absorbed and working on the brain within about five minutes.

Can you buy caffeinated chewing gum? Not that I know of. Wrigley used to make it, but not any more.

So next time you feel a “kick” within a few seconds of drinking some coffee, what you’re feeling is more a placebo effect and not yet the impact of the caffeine itself.