Zopyrus (Greek: Ζώπυρος; 1st-century BCE) was a surgeon at Alexandria, and the tutor of Apollonius of Citium and Posidonius.[1] He invented an antidote, which he recommended to Mithridates VI of Pontus, and wrote a letter to that king, begging to be allowed to test its efficacy on a criminal.[2] Another somewhat similar composition he prepared for one of the Ptolemies.[3] Some of his medical formulae are quoted and mentioned by various ancient authors, viz. Caelius Aurelianus,[4] Oribasius,[5] Aetius,[6] Paul of Aegina,[7] Marcellus Empiricus,[8] and Nicolaus Myrepsus.[9] Pliny[10] and Dioscorides[11] mention that a certain plant was called zopyron, perhaps after his name. Nicarchus satirizes a physician named Zopyrus in one of his epigrams.[12] Not to be confused with Zopyron.