Panacea is a remedy that supposedly would cure all diseases and prolong life indefinitely. Its creation was one of the best known goals of the alchemists. 
The Elixir of Life may be considered the achievement of Panacea, as Voldemort sought it out to regain a body after his original one was destroyed via a reflected Killing Curse, and it can extend life indefinitely as long as it is drunk regularly.
- Harry Potter and the Philosopher's Stone (film) (First mentioned)
- Harry Potter and the Half-Blood Prince (film) (First identified as Panacea)