A glass jar with a label in Greek

You pick up a small glass jar, about an inch across, filled with a milky fluid. A yellowed label on the outside has a word written in Greek "γλακτοφόρος" in faded ink across it.

You search the internet and find the word means "Milk-producing", which allows you to take a guess at what this potion does. You probably shouldn't drink it any time soon...