Alexander of Tralles, writing in the late sixth century, combined his wide-ranging practical knowledge with earlier medical theories. This article shows how clinical experience is used in Alexander’s works by concentrating on his therapeutic advice on epilepsy and, in particular, on pharmacology and the group of so-called natural remedies. I argue that clinical testing is used not only for the introduction of new medicines but also as an instrument for checking the therapeutic effect of popular healing practices. On another level, this article discusses Alexander’s role as the author of a medical compendium; it suggests that by marking the cases of clinical testing with a set of recurrent expressions, Alexander leads his audience to reflect on his medical authority and personal contribution.