Signals Report: Xylazine

Xylazine Has Spread to Every Region of the Country, Millennium Health Signals Report™ Shows

Xylazine, fentanyl and other potentially lethal substances frequently found together, report from more than 160,000 urine drug tests demonstrates

SAN DIEGO, Calif. – September 14, 2023 – According to the Millennium Health Signals Report released today, the powerful, veterinary tranquilizer xylazine—also known as “tranq”—was detected in urine drug tests from every region of the country, with the highest rates in the Eastern U.S. This analysis of the nationwide spread of xylazine is the most current and substantiative to date since xylazine use rose to prominence.

“Increased awareness of the threats posed by xylazine is needed among clinicians and public health officials across the U.S. and geographical changes in xylazine use should be monitored closely with timely and reliable sources of surveillance data,’ says Scott Walton, CEO. “Although xylazine use among those who use fentanyl is currently concentrated in the East, a 2022 DEA report suggested that xylazine appears to be following the same east-to-west path as fentanyl. Time will tell if this becomes the case. We will continue to closely monitor xylazine and provide real-time updates about any shifting use as part of our commitment to help prevent drug overdose deaths.”

Geographical Analysis of Xylazine Detection in Fentanyl-Positive Specimens: Pacific is 4%, Mountain is 2%, West North Central is 13%, West South Central is 5%, East North Central is 33%, East South Central is 19%, Mid Atlantic is 40%, South Atlantic is 22% and New England is 16%. The U.S. Total is 16%

Geographical Analysis of Xylazine Detection in Fentanyl-Positive Specimens

According to Leonard Kamen, DO, Clinical Associate Professor of Physical Medicine and Rehabilitation, Sidney Kimmel Medical College, Thomas Jefferson University Hospital, Philadelphia, “Xylazine has devastated our local community. The challenges it has brought are many because at present there are no treatments specifically approved for xylazine use nor any xylazine-specific overdose reversal agents approved for xylazine-involved overdoses. Clinicians should carefully monitor patients who report unusual drug effects when taking what they thought was fentanyl, or those who have the telltale skin wounds associated with xylazine use.”

Xylazine-Associated Polysubstance Use Rates are Significant

The report also identified that the use of multiple substances (i.e., polysubstance use) is significantly higher among those testing positive for fentanyl and xylazine compared to those who had used fentanyl but not xylazine. Specifically, prescription opioid, heroin, gabapentin, benzodiazepine, cocaine, fentanyl analogue, and methamphetamine use were all greater among those who had used fentanyl and xylazine.

“This is a substance no human being was meant to ingest and often people may be exposed to it without their knowledge, which increases the risk. Though the effects of xylazine cannot be reversed using naloxone, xylazine often is used alongside opioids, which naloxone can reverse, so it should be administered in a suspected overdose,” Chief Clinical Officer Dr. Angela G. Huskey at Millennium Health. “This is a dangerous situation, and it’s spreading rapidly. We are trying to sound the alarm on the need to integrate clinical monitoring into our national response so we can provide advance warning and know in real-time where people need help.”

The Millennium Health Signals Report™ provides a summary of America’s epidemic of illicit drug use and originates from Millennium Health’s Emerging Threat Intelligence (ETI) Program™. The ETI program provides real-time surveillance of drug use trends to help clinicians, researchers, public health officials, and policymakers address the significant increase in drug overdose deaths.


The Millennium Health Signals Report: Zeroing in on Xylazine: The First 100 Days After U.S. Emerging Threat Designation is an analysis of urine drug test results from more than 160,000 specimens collected between April 12th and July 20th, 2023. Millennium Health analyzed Xylazine UDT positivity in the fentanyl using population by U.S. Census Division. Co-detection of 9 illicit or non-prescribed drug classes with and without xylazine was also evaluated. U.S. Census Regions and Millennium Health statistical methods are available upon request.

Access the Millennium Health Signals Alert here.

About Millennium Health

Millennium Health is an accredited specialty laboratory providing medication monitoring via definitive urine and oral fluid drug tests to support improved clinical decision-making as part of treatment for millions of Americans with chronic pain, mental illness, substance use disorders, and other health conditions. Drug testing is used to obtain objective information about patients’ recent use of prescription medications and/or illicit drugs and helps monitor the effectiveness of treatment plans. We also conduct real-time tracking of emerging drug use trends to help researchers, public health officials, and policymakers address the significant increase in drug overdose deaths.

Media Contact

Jody Schneider
Millennium Health
(619) 917-6810