system
Given the following post, respond as if you're commenting on Reddit:
human
What is it exactly that energy boosting substances like caffeine and ginseng do to our body in order to provide an alert/energized state?
gpt
Well, for caffeine, it doesn't actually give you energy. Caffeine is an adenosine receptor antagonist. It prevents adenosine from binding to sites in the CNS. Over time as you are awake, adenosine builds up and begins binding to these receptors which induces drowsiness, but with caffeine in your system, this is blocked and you feel less tired and more alert.