While some pronouncements of expert treaty bodies have been considered ‘key catalysts’ for the development of international human rights law, others are only selectively referred to in legal practice. This article argues that the varying normative impact is due to the informal character of pronouncements. In the absence of treaty provisions specifying their legal effect, practitioners tend to rely on different factors and arguments when either drawing on or rejecting certain pronouncements. Scholars in turn face difficulties when trying to identify explanatory patterns within this diverging practice as the informal character confronts both international lawyers and international relations scholars with their respective methodological ‘blind spots’. In light of these intradisciplinary challenges, this article explores the extent as to which an interdisciplinary approach helps to assess the reasons for the varying impact of pronouncements. After analysing the factors determining their legal significance on the basis of State practice and the academic debate, this article identifies the drafting process as a factor which promises to be particularly insightful when explored from an interdisciplinary perspective and sketches out a framework for future research.