The only legal OTC drugs worth taking excluding RCs are nitrous, DXM and codeine. Don't even bother with MG seeds (they make you puke endlessly and when that wears off, your legs hurt so much presumably from vasoconstriction that you can barely move, they basically cause mild ergotism) or any deliriants (jimson weed, diphenhydramine, etc). Propylhexedrine is rubbish from what I've heard, and has way too many peripheral side-effects. Salvia isn't much fun, either.
If you want real drugs, buy real drugs, not OTC rubbish. Get a bag of weed, some opium, some MDMA (might be a waste of money though on an SSRI), some shrooms etc.