How Caffeine Masks Tiredness

Is your morning coffee actually giving you energy, or is it just hiding the fact that you’re

exhausted? Caffeine is what scientists call an adenosine receptor antagonist.

Throughout the day, a substance called adenosine builds up in your brain as a biological

signal that you need to sleep. Caffeine doesn't actually clear that adenosine away;

it simply plugs the receptors so your brain can't "read" the signal. It is essentially

a biological mute button for your tiredness. However, because its effect

on dopamine is quite weak compared to medical stimulants, it usually isn't strong enough to

manage pathological sleep disorders. Discover the surprising science behind the world's most popular