It's not a wonder drug or some kind of videogame-esq performance enhancer like mushrooms in mario. It's medicine.
A lot of these so called "smart drugs" or nootropics won't make you brainzilla overnight. You wont be a genius. The effects most of the time (unless you had an underlying condition) will be subtle at best. Most of these aren't designed to make people superhuman, they're designed to try to bring people back to "normal".
What about once you stop and still have to do work anyway? You might not be able to cope. Unless you're planning to never stop taking it?
These are medicines remember. They go through years and billions of dollars of testing but that doesn't mean we know everything about how they work, in some cases we know very little.
Sure, there might be relatively few apparent side effects now but what about if in 20 years we discover they cause supercancer...
Things like thalidomide for example seemed really good at the time but then we found out about horrible side effects.
If you think you need to take drugs at all to be able to function in your education you're either working way too hard or stressing way too hard. Go out and enjoy life.