Five years ago, during the first worldwide placebo conference held here, in Leiden, our city was nicknamed ‘Placebocity’. A nice nickname when you consider that placebo in Latin means “I will please you”. For the past 94 days, Leiden has proven to be very pleasing! In that respect, there’s no question of a placebo effect: test subjects who receive a placebo (a fake medicine without active substances) sometimes experience that the “medicine” works after all. The science behind this is not yet clear, making it an intriguing research subject.