Was thinking, instead of just mixing a poison to hurt someone, why not be given the choice to mix something that could paralyze someone.. or something that would have the affect of wither or weakness.. and that of dexterity, etc.

Interesting idea, but I'm not sure how you get the poison/effect to inflict an npc. do you dip a piece of bread in it? NPCs don't eat.

I haven't had much experience with poison mixing, but I agree it could do more than poison.

Currently its set up:

Get the ingrediants
Mix it up
Pour it onto/into something -- ex: a weapon or waterskin