An adulterant in fentanyl is creating a new crisis of withdrawal symptoms for users and provoking public concern in multiple U.S. cities.
The new drug, a veterinary sedative called medetomidine, is now widespread in the fentanyl turning up in Philadelphia, Pennsylvania, according to a report from a forensic testing lab. This crisis is not from overdosing on medetomidine, but from the withdrawal patients experience within hours of using.
On Dec. 19, 2025, New York State issued a health alert about medetomidine. The state Department of Health’s program monitoring illicit drugs found medetomidine in 37 percent of the samples of opioids tested. That number was just 4 percent in May 2024….
What to Know About the Drug Causing a Withdrawal Crisis in Fentanyl Users
