"One health potion, please, my good alchemist," says the adventurer on his first day.

Any good alchemist, or at least one that wants repeat custom, will take the young adventurer aside and explain that no such thing as a generic "health potion" exists. What we sell are transmutation potions, and they must be carefully calibrated, in the same way an armorer would not dream of fitting an orc with a set of gnome armor.

Each "healing potion" is unique, and contains within it a record of an individual's physical state at a moment in their life when they were whole and hale, typically distilled from a bit of hair or flesh donated to the alchemist in the days prior to the adventurer venturing forth. When imbibed, a potion is not healing their broken body so much as it is transmuting them back to this saved state, before the shattered bones, burns, and dragon bites occurred.

This is why these potions are so costly, since they require tailoring to the individual. There are cheaper, blended options, where an alchemist combines the hair of a dozen healthy male elves or female fetchlings or male trolls, for example, to produce a larger batch of a more generalised product, but the effects are very noticeably diminished, and they should still only be drunk within each intended species. The search for a truly universal potion of healing sits alongside the philosopher's stone itself.

It is also why correct labelling is so important. Adventurers must never mix up or share potions with their allies, lest they want to start resembling them.