For ancient Christians, the most dangerous enemies are those within the Christian “body.” Heretics are the stock villains of Patristic literature. The late fourth-century bishop Epiphanius of Salamis, author of a work entitled Panarion, or Medicine Chest, is among the most inventive of the ancient heresiologists. Comparing heresy to disease, he also frequently portrays heretical leaders as effeminate. This paper seeks to build on prior scholarship that has emphasized Epiphanius’s prominent use of medical metaphors, on the one hand, and his feminized and eroticized depictions of heretics, on the other. Focusing on the convergence of these two rhetorical strategies, I will explore the resonance of Epiphanius’s heresiology with earlier medical literature in which effeminacy is represented as a disease. Just as disease may infect a body, so effeminacy may infect manhood. Thus, Epiphanius invokes the disease of effeminacy discussed by medical writers to construct a heretical villain notable for his insidiousness.