Fentanyl was developed as a drug that could relieve severe pain and assist doctors in performing complex surgeries. Due to its potent effects, fentanyl is often sold illegally as an ingredient in counterfeit opioid pills or mixed with heroin or cocaine. Because it is nearly impossible to gauge the strength of illegal fentanyl doses, tens of thousands of Americans have overdosed on the drug in recent years. This book provides information about the effects of fentanyl and how it contributes to the ongoing opioid crisis.

Who uses fentanyl? -- The history of fentanyl -- How does fentanyl work? -- The long-term effects of fentanyl -- Treating fentanyl addiction.