Ethnopharmacological relevanceThe debate on the food-drug continuum could benefit from a historical dimension. This study aims at showing this through one case: the food-drug continuum in Greece in the fifth- and fourth-century BCE. I suggest that at the time the boundary between food and drug – and that between dietetics and pharmacology – was rather blurred.Materials and methodsI study definitions of ‘food’ and ‘medicine’ in texts from the fifth- and fourth-century BCE: the Hippocratic texts, the botanical treatises of Theophrastus and the pseudo-Aristotelian Problems. To illustrate these abstract definitions, I focus on two substances: garlic and silphium.Results and discussionThe Hippocratics were writing in a context of increased professionalization and masculinization of medicine, a context in which dietetics became the most prestigious branch of medicine, praised above pharmacology and surgery. While medicine was becoming more specialised, professionalised and masculine, it avoided becoming too conspicuously so. The Hippocratic authors sometimes noted that medical discoveries are serendipitous and can be made by anyone, whether medically trained or not. By doing so, they allowed themselves to integrate common knowledge and practice into their writings.ConclusionIn the context of the professionalization of ancient medicine, the Hippocratic authors started to address the difference between food and medicine. They saw, however, some advantage in acknowledging the continuum between food and medicine. Scholars should avoid drawing too strict a boundary between ancient dietetics and pharmacology and should instead adopt a multi-disciplinary approach to the therapeutics of the Hippocratic texts.