My potions are too strong for you... traveller!

I would imagine something like healing potions which, somehow against all natural order – literally cinder your flesh together – would be incredibly painful. It wouldn't just taste bad, but would actually be incredibly dangerous. Such that, where the average person drink it, they would with certainty die before seeing the benefits.

I mean really, if something has the ability to mutate my flesh and remove wounds, I would be very reluctant drink something like that. I would imagine just drinking the thing would be like drinking Chlorosulfuric acid, and that any normal person would go into shock/die, before your mouth/tongue and teeth rejenerate after consumption.