Two kinds of sources are available to the historian to reconstruct the first centuries of the history of Mithradates' antidote: biographical information on Mithradates' interests in medicine, and a series of recipes. In this paper I argue that we cannot reconstruct the original recipe of Mithridatium from our existing sources. Instead, I examine how the Romans remodelled the history of the King's death and used the royal name to create a "Roman" drug. This drug enjoyed a huge popularity in the first centuries of the Roman Empire. An Emperor, Marcus Aurelius, consumed it as well as members of the upper class; and many highly literate physicians recommended it notwithstanding the medical sect they were belonging to. With all its expensive ingredients, and its claim to work as a panacea, Mithridatium responded to a real demand in a Roman Empire at its commercial and political apogee.