Horklump juice is a substance extracted from Horklumps. It can be used in a range of healing potions, including the Wiggenweld Potion. One can purchase Horklump juice at one of the apothecaries in Diagon Alley.
- Harry Potter and the Philosopher's Stone (video game) (First mentioned)
- Harry Potter and the Chamber of Secrets (video game) (Mentioned only)
- Harry Potter and the Chamber of Secrets (film) (First appearance)