Ginger Snaps (2000)

Two teenage sisters, Ginger and Brigitte are two outsiders at school because of their obsession of death. They have made a pact about dying together and imitated 1001 arts of dying for their school project. However, their life is about to change forever when Ginger is attacked and bitten by a werewolf. Brigitte tries to find a cure to save her sister with the help of Sam, a local doper before Ginger is getting out of control because of her blood thirst.