Speedily Stolen Slaves' Salve

 Speedily Stolen Slaves' Salve is a potion carried by Baeloth Barrityl, a recruitable companion character found (in Baldur's Gate: Enhanced Edition only) in the Larswood area. The in-game description seems to suggest that its benefits, if any, are not what they seem.

In-Game Description
"When wholly consumed, this oddly murky potion appears to restore 9 Hit Points to the person. The effect is instantaneous and the potion is destroyed in the process."