Heroin is an illustrated history of Canadian heroin regulation over two centuries. Through the lens of harm reduction, Susan Boyd points to our failure to address the illegal overdose death epidemic caused by criminalizing drug users and to the decades of resistance to these policies. Heroin, discovered in 1898, was heralded as an important medicine and successfully marketed as a pain reliever and cough suppressant. Until the early 1950s, heroin was prescribed for therapeutic use in Canada. Yet, illegal heroin use became the focus of drug prohibition advocates and law enforcement who painted it as highly addictive and destructive. Systemic racism was the impetus for our first anti-heroin laws. The race, gender and class of users influenced drug control which, by the 1930s, became the focus of law enforcement. Flawed ideas about heroin and people who used the drug shaped drug law and policy for decades--and continue today.