While recovering from a cold, I recalled reading that Ancient Nubians brewed antibiotic beer:
A chemical analysis of the bones of ancient Nubians shows that they were regularly consuming tetracycline, most likely in their beer. The finding is the strongest evidence yet that the art of making antibiotics, which officially dates to the discovery of penicillin in 1928, was common practice nearly 2,000 years ago.
“We tend to associate drugs that cure diseases with modern medicine,” Armelagos says. “But it’s becoming increasingly clear that this prehistoric population was using empirical evidence to develop therapeutic agents. I have no doubt that they knew what they were doing.”
Even the tibia and skull belonging to a 4-year-old were full of tetracycline, suggesting that they were giving high doses to the child to try and cure him of illness, Nelson says.
Essentially the research says that these ancient Africans knew how to produce an antibiotic that was only rediscovered in the 1940s. I think that makes a nice variation on the usual “potion of healing”, and is something of a double-edged sword: it can help cure sick characters, but at the cost of getting them drunk. Or what if all these potions are just charlatanry and potions of healing, curing, courage, strength etc are just flasks of brandy? They pop the cork, take a big draught and think “Yes, I do feel stronger”.