Though the influence of Evidence Based Medicine (EBM) has helped ensure that trial results have become more important for public policy and clinical practice in the last twenty years, most of the funding for these trials still comes from the private sector, i.e. the pharmaceutical industry. This chapter explores efforts to educate ordinary clinicians about the ways in which such trials may be ‘biased’ but also work more subtly as forms of ‘agenda-setting’ for their sponsors. Its particular focus is the medical journal, and attempts to make this a site for collective appraisal of trial data. Can this professional critique provide an adequate defence against what social scientists have called ‘corporate science’? What kinds of knowledge are marshalled in the attempt, and how are they given credibility?