Who we choose as a partner depends in part on who we find attractive on the outside. Scientists have long wondered whether potential partners can also sense a woman’s fertility, for example through subtle changes in her body odour. Researchers from Leipzig University, the Max Planck Institute for Evolutionary Anthropology and the University of Göttingen have now turned their attention to this question. In a new study, they not only looked at how men rated women’s odours on different days, but also, for the first time, carried out a chemical analysis of the odour samples. Using both methods, they found no evidence that women smell more attractive to men on their fertile days.