The 21st century has seen the proliferation of technologies and sources of information on issues of all kinds, including sexuality. Amid debates about the role of social media and the internet in mediating sexuality, questions about credible, reliable and objective sources of information have also arisen, particularly in relation to young people's knowledge-seeking. Drawing on theorisations of sexual citizenship, Foucault's notion of the 'episteme', and the work of science and technology studies scholar John Law, this article examines a 'collateral reality' produced by contemporary demands on young people to source, assess and act on sexual health information. Using interviews with 37 young people living in Australia, the analysis identifies a range of approaches to sexual health-seeking practices, key dynamics in the construction of reliability and fact, and the extent and nature of the accommodations young people report making to navigate incomplete and unreliable information. With the contemporary self increasingly framed through the ability to discern truth from falsehood, reality from fake news, these demands and choices have significant implications for qualification as the proper modern citizen. Accommodating information weaknesses and gaps in sexual health information, we argue, produces what we call contemporary 'epistemic citizens'; young people explicitly aware of the limits of official knowledges about sex and sexualities, and of the expectation that individual citizens must either content themselves with officially constituted sexual selves or else seek and enact marginal or unofficial alternatives using sources generally denigrated as unreliable. As we will conclude, current forms of sexual health information and related calls for youth literacy operate as a mechanism for generating a specific modern form of epistemic citizenship. Future sexuality education might consider ways to support even more literate, sophisticated epistemic citizens relieved of the responsibility to piece the truth together on their own, and who in turn feel more included.