Fakes have become a matter of concern across global health. Commissioning inquiry into presumed fake practices in global health requires both a pre-existing sense of what would constitute real provision and a suspicion that it is not being offered. In this Position Piece, we analyse the research methods being used to identify and reveal other—presumed—fakes in global health provision. We put forward the concept of the ‘second-order fake’—the fake that is used to reveal a fake—to draw attention to the methodological politics at stake in the use of the fake. By reviewing historical cases of the creation of methods of deception, we analyse the assumptions they bring into global health from other disciplines. We foreground the promises of revelation that are embedded in probes that rely on fakes to uncover fakes. We suggest that despite the growing prevalence of methods which themselves deploy fakes to find fakes, these techniques bring us no closer to understanding the lived ambiguities of everyday practices of fakery.