Modern medicine has significantly advanced in the last few decades as incredible breakthroughs have made it possible to successfully treat and even eradicate many serious ailments. But we still rely on practices that are out of date, argues Paul Offit, who debunks 15 common medical interventions that have long been considered gospel despite mounting evidence of their adverse effects, from vitamins, sunscreen, fever-reducing medicines, and eyedrops for pink eye to more serious procedures like heart stents and knee surgery. Analyzing how these practices came to be, Offit discusses the biology of what makes them so ineffective and harmful, and takes aim at the medical culture that continues to promote them.