My dissertation examines the intersection in the century between literary representations of opium-use, medical theories of substances, and Sino-British relations. It argues that opium’s effects on the medicalized body (in and out of fiction), by providing ways to envision Britain’s clash with the declining Sinocentric system, played a crucial role in shaping Britain’s project of modern self-making and empire-building. Building on opium’s many racial and imperial implications, my project advances scholarship in nineteenth-century studies by asking how medical studies and imperialism converged in representations of opium use and abuse. I divide the points of convergence into five categories, each of which my dissertation examines chronologically via one or two literary works from the 1820s to the 1890s: vigorousness; intoxication; physiognomy; addiction; and addiction treatment.