Coffee and Caffeine FAQ

Is there a way to reduce the quantity of caffeine on your body, like an antidote?
For example, if you take an expresso or a certain amount of coffee to keep you awake (for finish a work or study), but then you realize that you don't need to be awake all night, is there something that cuts the effect of caffeine (food or drink for example) you have on your body?

I've searched in your FAQ, but didn't find anything.

Thanks in advance
Tiago
Portugal