This article is a fascinating review about how reporting bias can affect our knowledge about health treatments. It examines how certain studies, or outcomes, do not get published and highlights several cases in which this non-reporting has been harmful to patient care. Although the examples are mainly given from commercial pharmaceutical interests, the same issues can apply for complementary medicines: the case of evening primrose oil for atopic dermatitis is mentioned here. This full text of this article is published as open access; it is free to read by clicking the link below.