The Uphill Fight Against Fake Prescription Drugs

Drug companies and law enforcement struggle to stop online sales of counterfeit versions of medications like Xanax laced with fentanyl that can kill unsuspecting users

Tosh Ackerman took part of what he thought was a Xanax pill to help him sleep one night three years ago. His girlfriend found the 29-year-old dead the next day.

The Xanax he obtained from an acquaintance was counterfeit, says his mother, Carrie Luther, who lives in Mount Hermon, Calif. Toxicology reports found it contained a fatal dose of fentanyl, a synthetic opioid often produced illicitly for the black market.

“It...