Some content in this article is derived from information featured in Harry Potter and the Cursed Child, and, as such, spoilers will be present.
The Restricted Register was a list of potion ingredients that were controlled (presumably by the Ministry of Magic). Boomslang skin and lacewing flies were not on this register, despite the fact that both were key ingredients in the Polyjuice Potion.
- Harry Potter and the Cursed Child (Mentioned only)
- Harry Potter and the Cursed Child (play) (Mentioned only)