A Cadava potion is used in the Romeo & Juliet quest. The player would give the Apothecary Cadava berries in order to receive a Cadava potion. The Cadava potion was then used to fake Juliet's death so Romeo could meet her. Drinking this potion will give the message "Oh dear. You are almost dead" similar to the message you get when dying saying "Oh dear. You are dead."