Overdose deaths involving stimulants and opioids simultaneously have raised the specter of widespread contamination of the stimulant supply with fentanyl. This study investigated the extent to which cocaine and methamphetamine also contained fentanyl. Data was acquired from a drug checking service which analyzed samples submitted by drug users, health departments, medical clinics, and others.

Study results: https://www.sciencedirect.com/science/article/pii/S0376871623012231?dgcid=rss_sd_all