It is used as a potion ingredient and is sold at the apothecary in Diagon Alley for 4 galleons a bottle. It is also kept in the Hospital Wing. Castor oil is one of the ingredients needed to brew a Love Potion Antidote.
Behind the scenes
- In the real world, Castor oil has applications in areas such as food preservation and medicine.
- Harry Potter and the Half-Blood Prince (video game) (First appearance)