Consumer discernment of fentanyl in illicit opioids confirmed by fentanyl test strips: Lessons from a syringe services program in North Carolina

The United States (U.S.) continues to witness an unprecedented increase in opioid overdose deaths driven by precipitous growth in the supply and use of illicitly-manufactured fentanyls (IMF). Fentanyl's growing market share of the illicit opioid supply in the U.S. has led to seismic shifts in the composition of the country's heroin supply. The growth in fentanyl supply has transformed illicit opioid markets once offering heroin with fairly consistent purity and potency to a supply overpopulated with fentanyl(s) of inconsistent and unpredictable potency. In response, people who inject drugs (PWID) have developed a number of sensory strategies to detect fentanyl in illicit opioids. The current study examined the accuracy of sensory discernment strategies by measuring study participants’ descriptions of the last opioid injected and checked with a fentanyl test strip (FTS) by that test's positive/negative result. The primary objective was to determine associations between FTS results and descriptions of the illi it opioid's physical appearance and physiological effects.