The emergence of the animal tranquilizer xylazine as a fentanyl adulterant has prompted law enforcement officials to agitate for new legal restrictions and criminal penalties. That response is fundamentally misguided, because the threat it aims to address is a familiar consequence of prohibition, which creates a black market in which drug composition is highly variable and unpredictable.
Xylazine, a.k.a. "tranq," was first identified as a drug adulterant in 2006, and today it is especially common in Puerto Rico, Philadelphia, Maryland, and Connecticut. The combination of fentanyl and xylazine poses special hazards.
