JESSIE WAS ON AMPHETAMINE, NOT CAFFEINE PILLS!
http://www.ew.com/article/2016/11/15/saved-by-the-bell-jessie-speed-caffeine
shareSpeed wouldn't have worked, either. That's too extreme for the show's tone.
I think if she took some kind of prescription medication that was meant for someone else and started abusing it, then that would've worked.
Either put on these glasses or start eatin' that trash can