“When it comes to clinical trials, few issues are simple. And many are controversial” wrote the Science correspondent Gary Taubes in 1995.1 Taubes' dictum seems to be at odds with the public model of the randomised clinical trial as a most helpful tool to relieve medical practice of that most feared element known to scientists and regulators: subjectivity. Are most doctors and regulators who firmly believe in the randomised controlled trial as the key to an “evidence based medicine” mistaken? Given an ideal world without social, professional, and economic interests affecting judgments of the efficacy and risks of medical treatments, one might have answered “no.” It is impossible, however, to conceive of such a trial taking place in a human vacuum. Conducting randomised controlled trials involves establishing links and commitments between many different individuals and organisations, including clinicians, laboratory researchers, patients and their families, regulators, and drug companies. In being shaped by the specific context of medical practice, clinical trials—even the most sophisticated randomised controlled trials—are not value-free measuring devices that objectively evaluate the efficacy of new treatments. Like any other medical device associated with our daily lives, randomised controlled trials incorporate the beliefs and ideas of the people who developed them and then are moulded by those implementing the methodology.2 I use here the story of interferon to illustrate the complexities surrounding the application of this supposedly value-free research methodology. Interviews referred to in the article were between myself and the person cited.