“You are what you eat.” Never is this truer than when we take medications-from beta blockers and aspirin to Viagra and epidurals-especially psychotropic pills that transform our minds as well as our bodies. Meditating on how modern medicine increasingly measures out human identity not in T. S. Eliot’s proverbial coffee spoons but in 1mg-, 5mg-, or 300mg-doses, Pill traces the uncanny presence of psychiatric pills through science, medicine, autobiography, television, cinema, literature, and popular music. Ultimately, it argues that modern psychopharmacology reveals a brave new world in which human identities-thoughts, emotions, personalities, and selves themselves-are increasingly determined by the extraordinary powers of seemingly ordinary pills.