A new study from the National Institute of Standards and Technology (NIST) reveals how harmful substances mixed into the illicit fentanyl supply vary across the country and change over time.
NIST chemist Edward Sisco and colleagues analyzed 4,563 samples of drug residues collected nationwide between January 2024 and June 2026. Their findings, published in Drug Testing and Analysis, show how the prevalence of adulterants—including anesthetics, industrial chemicals, and veterinary sedatives—shifts by region and season.
Public health officials and law enforcement have lacked detailed and timely information on these adulterants, which can be toxic and potentially deadly. Sisco's team used a technology that identifies trace amounts of unknown compounds within seconds.