Xylazine-Fentanyl Positivity and Concentration in Urine Drug Tests

Source:

Sugarman OK, Marks C, Whitley P, Saloner B, German D. Xylazine-Fentanyl Positivity and Concentration in Urine Drug Tests. JAMA Netw Open. 2026;9(7):e2622473. doi:10.1001/jamanetworkopen.2026.22473

Key Points

Question  How are the presence and concentration of xylazine with fentanyl changing in the US over time and region in the current phase of the opioid crisis?

Findings  This cross-sectional study analyzed 42 307 fentanyl-positive urine drug testing (UDT) samples collected between March 2023 and September 2025 that were also tested for xylazine. In the East and West US, xylazine detection increased while concentration in UDT samples sharply decreased.

Meaning  This cross-sectional study found that the concentration of xylazine in the US drug supply may be decreasing, but xylazine with fentanyl was still present and spreading.