 The study aims to describe the characteristics of PREP-related posts on Instagram, including source type, image types, and textual contents, using crowd-tangle search and a qualitative coding methodology. It found that three-quarters of the posts were posted by organizations, with more than half including a photograph or an infographic. While more than half defined PrEP, fewer posts promoted its use, explained how it works, or included information on its effectiveness or who can use it. The study also found statistical differences between source types, with organization posts more frequently containing information about who can use PrEP and individual posts more frequently describing adverse effects. This article was authored by Eric Walsh-Bohi, Rebecca Fagan-Houghton, Claire Lang, and others.