Non-beneficial paediatric research is vital to improving paediatric healthcare. Nevertheless, it is also ethically controversial. By definition, subjects of such studies are unable to give consent and they are exposed to risks only for the benefit of others, without obtaining any clinical benefits which could compensate those risks. This raises ethical concern that children participating in non-beneficial research are treated instrumentally; that they are reduced to mere instruments for the benefit of science and society. But this would make the research (...) incompatible with the widely endorsed principle of the primacy of the human subject, which stipulates that the interests of the participating individual should prevail over the interests of science and society. This paper deals with this conflict. It analyses solutions to this problem developed in the literature, and shows that they are unsuccessful. Finally, it offers a new idea of how to reconcile the conduct of non-beneficial paediatric research with the PP. The paper argues for a new formula of the PP, and shows that it implies a specific non-comparative definition of the minimal risk threshold. (shrink)