If you've been following the overdose crisis, you may have heard a new word in recent years: xylazine, or "tranq." It's a sedative used in veterinary medicine that is now showing up in the illicit drug supply — primarily mixed with fentanyl — from coast to coast. Understanding xylazine matters for anyone in recovery, anyone who loves someone who uses drugs, and anyone working on the front lines of harm reduction. Here's what the evidence says.
Xylazine is a powerful sedative and muscle relaxant approved by the FDA for use in animals — it's used by veterinarians to sedate horses, cattle, and other large animals. It has never been approved for use in humans. It works on the central nervous system in a fundamentally different way than opioids: it is an alpha-2 adrenergic agonist, not an opioid, so standard overdose-reversal medications like naloxone (Narcan) do not work against it.
On the street, it's called "tranq." When mixed with fentanyl, the combination is sometimes called "tranq dope." People may not know they're consuming it — it's mixed into drugs without the user's knowledge or consent.
The spread of xylazine has been rapid. A CDC study found that the share of fentanyl-involved overdose deaths with xylazine detected rose 276% between January 2019 and June 2022 — from 2.9% to 10.9% across 21 reporting jurisdictions. By the time the DEA issued its national Public Safety Alert in March 2023, xylazine was being found across the country. As of October 2024, the DEA has detected xylazine in 49 of 50 states.
A separate DEA laboratory analysis found that in 2022, approximately 23% of fentanyl powder and 7% of fentanyl pills seized by law enforcement contained xylazine. In April 2023, the White House Office of National Drug Control Policy (ONDCP) formally designated the combination of fentanyl and xylazine as an emerging drug threat to the United States — the first time that designation has ever been applied.
When xylazine is mixed into opioids like fentanyl, the risk profile of an overdose changes in important ways:
Beyond overdose risk, xylazine causes a distinct and alarming physical harm: severe skin ulcers. These wounds — sometimes called "tranq wounds" or "tranq burns" — develop at injection sites and, unusually, also elsewhere on the body even when drugs are not injected at those locations. Researchers believe xylazine causes the wounds by severely constricting blood vessels, cutting off circulation and causing tissue death.
These wounds are painful, slow to heal, prone to infection, and can be severe enough to require surgical debridement or, in extreme cases, amputation. The FDA alerted healthcare professionals about this risk in November 2022, and wound care for people exposed to xylazine has become a focus of harm reduction and clinical care programs in cities where tranq is prevalent.
Here is the most important practical point: if you suspect an overdose and xylazine may be present, still give naloxone. This is the guidance from the CDC, SAMHSA, and NIDA. Because xylazine is almost always found mixed with opioids like fentanyl, naloxone can still reverse the opioid component and save the person's life — even though it won't reverse the xylazine itself. Always call 911 immediately, give available doses of naloxone, support breathing, and stay with the person until help arrives.
Expanded naloxone access, combined with growing awareness of xylazine, is essential. See our guide to getting free naloxone and using it step by step.
Even as communities have begun to adapt to xylazine, surveillance data suggest the drug supply is shifting again. Medetomidine — a stronger veterinary sedative in the same drug class as xylazine — has begun appearing in the illicit supply. Data from the National Drug Early Warning System (NDEWS) found medetomidine detected in 37% of opioid samples in October 2025, up sharply from just 4% in May 2024. Like xylazine, medetomidine is not reversed by naloxone. Public health researchers are monitoring this trend closely.
Need help or information? Call or text 988 (Suicide & Crisis Lifeline) for crisis support. For substance use treatment referrals, call SAMHSA's free, confidential National Helpline at 1-800-662-4357, available 24/7. In an emergency, always call 911.
This article shares public-health information from trusted national sources for educational purposes. It is not medical advice. In an emergency, always call 911. If you carry naloxone, follow the instructions included with your specific product.