How do you cure a werewolf?

Werewolves do not actually exist, so if a person claims to be a werewolf, the cure is simply to realize that they are not actually a werewolf.

According to mythology, you can kill the one that bit you in the first place, you can exhaust yourself (historically might have been a way of getting a lot of free work out of an unfortunate person), injection of extract of monkweed, etc.