Seeking for Sleepiness Potion

Off course the natural answer will be “sleep”. But what I’m talking here is not in a natural circumstance. We have enough rest at night, enough energy to face the day, somehow this evil sleepy thing always try to control our consciousness state.

Imagine that you’re in the class and then got boring whether because of the subject, overheat temperature (due to non working AC), or the lecturer is not that appealing and don’t have any sense of humor. As time goes by, your eyes start to feel heavy. Since you respect the lecturer, you’re trying hard not to close the eyes. The more you’re trying to wake up, the heavier you eyes got. Gosh, so suffer and hurt. You start thinking or hallucinate that you might get eyes muscle cancer! And suddenly, you’re fall asleep! Lucky case, nobody notice you. Worst case, get in caught by the lecturer and he made you do something embarrassing.

The point is overloaded boring in whatever condition will make you sleepy.
I do some action to prevent sleepiness/drowsiness. Bring some snack to make my mouth and brain busy by eating them sneakily, read a book, chat with someone who sat beside me (if they’re eager to chat). Apparently, all of those actions are not effective enough.

So, is there any creative or powerful solution to cure sleepiness/drowsiness that I mention above?
I’ll be thankful. To me, this is a serious issue because I’ve been through some embarrassing thing coz of this. Moreover, there is paranoid thinking popped up on my mind which is I might have diabetes.. Oh My God! Could it be? Could it be? (too much commercial watching, i guess....)