Dealers add fentanyl, which is up to 100 times more potent than morphine, to heroin and counterfeit tablets made to look like genuine prescription medications. Adding a few milligrams gives a powerful kick; a few more turn deadly.

In short, most of the people exposed to—and dying from—fentanyl didn’t think they were buying it and didn’t want to use it. Rather than increasing the number of users, fentanyl is driving up the death rate.

This distinction is important: It means our traditional methods for responding to drug epidemics won’t reverse the death toll. Usually government agencies focus on preventing experimentation, reducing accessibility of drugs, and treating individuals to suppress demand. These efforts remain valuable, but they won’t immediately curb overdose deaths in places that are drowning in fentanyl.

It is better to conceptualize the fentanyl problem like a poisoning outbreak. The poison is out there—but how can exposure to it be minimized? How can its spread to other regions be contained?