Carlyn Zwarenstein is the author of On Opium: Pain, Pleasure, and Other Matters of Substance, and its predecessor, Opium Eater: The New Confessions, a Globe & Mail best book of 2016. She has been a science and health writer at Salon.com, and now writes most often about biology and the intersections between science and power. As an independent journalist, Carlyn has written for publications ranging from Our Times to High Times and from the Washington Post to Canadian Geographic. She lives in Toronto.