Book excerpt: Many people believe that everyone who uses heroin is addicted. In fact, this is true of only about 20 percent of heroin users. By clearing up common misconceptions like these, this book provides information that can save the lives of people using the drug. The author recounts heroin's history, details its chemistry, tells what users need to know to avoid addiction, and demystifies the life of a user: from buying to administering to detoxing and staying clean.