May I ask? Do you mean Lust potion or Love potion? Because Lust potion can only use with enemies during battle except some enemies that immune or don't have any sexual desire like Hornet, Zombie, Skeleton, etc.
But Love potion can use during a battle to gain more affection with them. And also can use for some events with some characters, like Bernard, Korg , Blake, Barrel, Feliar, Xeroth, Harold.