Lethal dose Use a real penny to adjust the scale of the image in your device. Larger Smaller

Unlike many opioids in which prescription medicine is diverted for abuse, the street supply of fentanyl comes primarily from illegal production.

It can be lethal at the 2-milligram range (amount of powder shown to scale next to a penny in the photograph), depending on route of administration and other factors.

Because fentanyl is so cheap and readily available, dealers mix it into heroin, making heroin deadlier. Officials in New York City warned in 2017 that it was being mixed into cocaine, as well.