Elixir of Life

Anyone who drinks the Elixir of Life goes on living, provided they keep drinking it. It is drawn from the Philosopher's Stone, and alchemy has long held the making of a panacea as one of its three great aims, a remedy that cures every illness and prolongs life without limit; the Elixir is the nearest anyone has come to it. Nicolas Flamel is the only known maker of the Stone, which he produced in the fourteenth century, and he and his wife Perenelle have extended their lives on the Elixir ever since. Its weakness is that the supply can be spoiled: a contaminated batch may simply end the immortality, or turn to poison outright. Hogwarts forbids the Elixir as a subject of study, the staff fearing that a student who set out after it would be swallowed by the search, though the Alchemy shelves in the library carry a good deal about the Stone itself.