Hate Potion

A Hate Potion is a potion which reveals the worst traits and habiats of a particular person to the drinker.

The Hate Potion was recommended by the Daily Prophet's advice column for witches and wizards who are emotionally attached to a person who does not return their feelings. Although not guaranteed for a person to completely lose their feelings for a loved one, it does show the drinker the person's worst traits and habits, and so discourages them from creating a relationship with that person.