Preference for drugs containing fentanyl from a cross-sectional survey of people who use illicit opioids in three United States cities.

•A quarter of surveyed street-based people who use drugs reported a preference for fentanyl.•Fentanyl preferers were younger, non-Hispanic white, and daily users of drugs.•Frequency of use, not route of administration, indicated fentanyl preference.•Exposure to fentanyl among daily users was not differentiated by fentanyl preference.