nootropics

Modafinil is a class above caffeine.

→ Less addictive
→ More powerful and longer-lasting
→ Little to no impact on falling asleep (if taken early in the morning)
→ Alleviates sleep deprivation

I don't understand why it requires a prescription while caffeine is available OTC.

Co-Founder at sablier.com, and open-source developer. I have a broad range of interests, including longevity, epistemology, physics, and psychology.

I work in medicine and can tell you that i have had a number of patients have negative reactions to modafinil/armodafonil. The most common negative reaction is anxiety attacks, second most common is Arrhythmias. Still not a bad medication if used properly

Fair, but we need not stop promoting compounds because some people will respond badly to them.

For example, how many cases of anxiety attacks and arrhythmias does caffeine cause everyday?

Absolutely, caffeine definitely causes more issues on a net basis. My point is that modafinil isnt a panacea and based on the percentage of patients that have a reaction to modafinil vs caffeine, modafinil will be higher.
With that said, if you can go w/out any substance, that is better all around.