Where do we see xylazine?

A powerful sedative, xylazine is sometimes added to illicit opioid formulations, usually those involving fentanyls, to extend the feeling of relaxation. Although legal for veterinary use (usually with large animals), national law enforcement drug checking indicates that much of the xylazine seized is of greater purity than that supplied for veterinarians. It has been prominent on the East Coast for many years. In areas with more experience with xylazine, repeated use appears to be associated with flesh wounds and infections. Due to the health risks of xylazine in the drug supply, we focus here on all samples positive for xylazine.

First, we show community drug checking samples positive for xylazine by quarter, broken out by those found with fentanyls and those not found with fentanyls (which is rare). Initially, "all other samples" is hidden to focus on xylazine-positive samples, but if you click on that entry in the legend, you can see the relative prevalence of xylazine over time. Hover over a data point to see the percentage of all samples (if all other samples is in the graph) or of xylazine-positive samples (if all other samples is hidden).

While the graph above shows the share of all tested samples positive for xylazine, the graphs below take those positive samples and looks at what they were reportedly sold or given as. Here, in addition to our usual key "sold as" categories, which are not mutually exclusive, we add an indicator for being sold as none of these key categories.

Below we present the drugs found alongside xylazine in confirmatory testing results. Most xylazine is found with fentanyl and/or related substances (analogues or precursors). Note that fentanyl precursors are fentanyl-specific impurities, while the substances in the impurities category repesent chemicals or compounds that remain after processing or synthesis of other drugs, such as heroin (e.g., noscapine and papaverine) or methamphetamine (e.g., N-acetylmethamphetamine).

Data notes

Drug testing sites can do little about potential cross-contamination: The container a client used may or may not have been used before. Therefore, any unusual combination may be due to cross-contamination and not represent drugs actually sold together. Results are cumulative. For more details on drug categories named above, click here.