"I don't know how you can overdose smoking them:" Perceptions of overdose risks among persons who use illicit fentanyl-laced counterfeit pills

Aims: Illicitly manufactured fentanyl (IMF) remains the primary driver of overdose mortality in the US. Western states saw significant increases in IMF-laced counterfeit pain pills ("blues"). This qualitative study, conducted in Phoenix, Arizona, provides an in-depth understanding of how overdose-related risks are viewed and experienced by people who use "blues." Methods: Between 11/2022-12/2023, the study recruited 60 individuals who used "blues" using targeted and network-based recruitment. Qualitative interviews were recorded, transcribed, and analyzed using NVivo. Results: The sample included 41.7 % women, and 56.7 % whites. 55.3 % had prior overdose, but most (62.2 %) rated their current risk as none/low. Risk perceptions centered on a multi-level calculus of drug market conditions, individual vulnerabilities, and behavioral factors. Smoking was considered a "normative" way of using "blues", and most viewed it as protective against overdose in comparison to injection and other routes of use. Drug market conditions and the unpredictability of "blues" were emphasized as important factor of overdose risk. However, some believed that over time, the quality/consistency of "blues" improved, and they became less risky. Many also expressed fears about the emerging local availability of powder fentanyl and its risk. Views about safer dosing, polydrug use, tolerance, and health emphasized personal responsibility and individual vulnerability to overdose risks. Discussions of protective behaviors, including take-home naloxone, varied bases on the perceptions of overdose risks. Conclusions: The findings emphasize the need for close monitoring of local IMF markets and design of comprehensive interventions and risk communication strategies to address perceptions that minimize IMF-laced counterfeit pill risks.