Xylazine (“Tranq”): The Animal Tranquilizer Making Fentanyl Even Deadlier

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An animal tranquilizer never intended for people has infiltrated the U.S. illicit drug supply, creating a new dimension to the nation’s overdose crisis. The drug is xylazine—street name “tranq“—and it’s almost always mixed with fentanyl.

The U.S. Drug Enforcement Administration (DEA) calls this combination “the deadliest drug threat our country has ever faced.”

This mixture poses a complex public health challenge for three primary reasons: it dramatically increases the risk of a fatal overdose, its effects are not reversible by the opioid antidote naloxone (Narcan), and it causes horrific, flesh-rotting skin wounds that can lead to amputation.

In response to the rapidly escalating threat, the White House has officially designated fentanyl combined with xylazine as an “emerging threat.”

What is Xylazine? From Veterinary Medicine to Street Poison

Xylazine has two faces: in one context, it helps save lives, while in another, it destroys them.

A Critical Tool in Veterinary Medicine

Bayer synthesized xylazine in 1962. The FDA approved it for veterinary use in 1972. It’s now essential for vets working with large animals—a powerful sedative and pain reliever for cattle, horses, and deer. The American Veterinary Medical Association says there’s “no practical alternative” for sedating large animals safely.

For animals, xylazine works beautifully. It binds to alpha-2 adrenergic receptors, blocking the release of norepinephrine and dopamine. The result: deep sedation, muscle relaxation, pain relief. And if something goes wrong, vets can reverse it with drugs like yohimbine or atipamezole.

But those reversal agents? Not approved for humans. Not safe for humans.

This critical role in agriculture and animal welfare creates a significant policy dilemma. Any effort to control the illicit supply must be carefully balanced to avoid disrupting the legitimate veterinary supply chain, which could endanger both animal welfare and the safety of ranchers and veterinarians who handle large, powerful animals.

The Rise of “Tranq”: Infiltrating the Illicit Drug Supply

Drug dealers sought out xylazine for very specific reasons.

Fentanyl’s high is intense but incredibly short-lived. Users come down fast and need another hit. Xylazine extends that high for hours—up to eight hours or more. Its mechanism of action differs fundamentally from opioids like fentanyl. Xylazine is an agonist at alpha-2 adrenergic receptors, which works to decrease the release of the neurotransmitters norepinephrine and dopamine in the central nervous system. This action results in profound sedation, muscle relaxation, and pain relief. In the trade, it “gives fentanyl legs.”

Plus, it’s dirt cheap. Chinese suppliers sell it online for $6 to $20 per kilogram. And since it’s not federally controlled, it’s easy to get. The same logic explains why medetomidine—an even stronger veterinary tranquilizer—started showing up in Michigan’s drug supply in 2024. When one adulterant gets attention, traffickers just move to the next one.

On the street, xylazine is commonly known by names such as “tranq,” “tranq dope,” or the “zombie drug.” In the illicit market, it is typically found as a powder, which is produced by cooking down the liquid veterinary solution.

This powder is then mixed into other drugs like fentanyl, heroin, and cocaine, or pressed into counterfeit pills designed to look like legitimate prescription medications such as Percocet or Xanax.

Add less fentanyl, bulk it up with xylazine, and suddenly drug dealers are making more money per dose while keeping customers hooked longer.

Hidden in Plain Sight

A critical aspect of this crisis is that many people are exposed to xylazine and do not know it. It is often a hidden ingredient in what they believe is a different substance.

However, while many are unwitting victims, some individuals who are aware of its effects intentionally seek out “tranq dope” for its longer-lasting high. Conversely, in-depth interviews with people who use drugs reveal that many others actively fear and try to avoid it.

They report that it diminishes the desired euphoric effects of opioids and are changing their behaviors—such as switching from injecting to smoking—to avoid the horrific wounds and other negative side effects.

The “Zombie Drug”: Devastating Health Consequences

The introduction of xylazine into the illicit drug supply has transformed the overdose crisis into a more complex and deadly public health emergency. It creates a cascade of severe medical problems that the U.S. healthcare system is often ill-prepared to handle, from naloxone-resistant overdoses to gruesome wounds and difficult-to-treat withdrawal syndromes.

The nickname “zombie drug” is more than media sensationalism—it reflects a profound combination of physical decay and public helplessness that fuels stigma and creates barriers to care for those affected.

A Deadly Combination: Compounding Fentanyl’s Dangers

Both fentanyl and xylazine are powerful central nervous system depressants, but they work through different biological pathways. When taken together, their effects are not merely additive but synergistic, meaning the combined effect is greater than the sum of its parts.

Xylazine dramatically worsens the respiratory depression (slowed or stopped breathing) caused by fentanyl, which is the primary mechanism of a fatal opioid overdose. The combination also leads to dangerously low blood pressure (hypotension), a severely slowed heart rate (bradycardia), and a drop in body temperature (hypothermia), pushing the body’s vital signs to critical levels.

Furthermore, xylazine induces a state of profound, prolonged sedation or unconsciousness that can last for hours. This “blackout” state leaves individuals extremely vulnerable to robbery, physical and sexual assault, and environmental exposure, such as freezing to death in winter or suffering heat stroke in summer.

This prolonged immobility can also lead to severe secondary injuries like compartment syndrome, a condition where swelling and pressure in a muscle compartment restrict blood flow, causing permanent muscle and nerve damage.

People overdosing on this combination sometimes collapse into the “fenty fold”—a stooped, rigid posture that’s become a grim signature of the xylazine crisis.

The Naloxone Complication: An Antidote Rendered Incomplete

Here’s the critical problem: xylazine isn’t an opioid. It doesn’t bind to opioid receptors. Which means Narcan—the drug that reverses opioid overdoses—can’t touch the xylazine part of the overdose.

You should still give Narcan. Almost everyone using xylazine is also using fentanyl. Narcan will reverse the fentanyl and might be enough to restart breathing and save a life.

However, even after naloxone is given, the person may not fully wake up or may continue to have dangerously slow breathing because the sedative effects of xylazine persist. This phenomenon of a “naloxone-resistant” overdose means that other life-saving measures are required.

This is why rescue breaths are critical. If you keep oxygen flowing into their lungs, you can keep them alive until paramedics arrive with more advanced support.

The “Flesh-Eating” Effect

The “zombie drug” nickname isn’t just media hype. It comes from the visually horrific effects of xylazine on human tissue.

Xylazine dramatically constricts blood vessels. Blood flow to your skin and soft tissue drops to dangerous levels (a condition known as ischemia). Without oxygen and nutrients, tissue dies. You develop open, painful ulcers covered with thick black dead tissue called an eschar.

These wounds can appear anywhere on your body, not just where you inject. Some doctors report seeing them even in people who only smoke or snort drugs with xylazine in them.

The wounds get infected easily. Infections spread. What starts as a small sore can become cellulitis, abscesses, necrotizing fasciitis (“flesh-eating bacteria”), or bone infections (osteomyelitis). Treatment requires surgery to cut away dead tissue. In severe cases, doctors have to amputate limbs to save lives.

Beyond Overdose: Withdrawal and Long-Term Harms

The dangers of xylazine extend beyond overdose and wounds. Repeated exposure leads to physical dependence, resulting in a unique and severe withdrawal syndrome that is distinct from opioid withdrawal.

Users report debilitating symptoms including severe anxiety, agitation, irritability, and sharp chest pains. Crucially, these symptoms are not effectively managed by standard medications for opioid use disorder (MOUD) like methadone or buprenorphine.

This makes addiction treatment profoundly more complex, as providers must attempt to manage two separate and severe withdrawal syndromes at the same time, often without established protocols, which can lead to patients abandoning treatment.

Chronic use is also associated with other long-term harms, including memory problems and cardiovascular damage.

Tracking the Spread: A National Public Health Emergency

Federal data shows the scale of this crisis. But keep in mind: these numbers are likely underestimates. Many jurisdictions don’t test for xylazine routinely, and reporting isn’t standardized. The DEA admits that incomplete testing means we’re only seeing part of the picture.

Data Deep Dive: Quantifying the Crisis

In 2022, the DEA analyzed drugs they seized nationwide:

• 23% of fentanyl powder contained xylazine
• 7% of fentanyl pills contained xylazine
• Xylazine showed up in 48 of 50 states

By 2023, those numbers climbed:

• 30% of fentanyl powder contained xylazine
• 6% of fentanyl pills (slight decrease)

The Death Toll

CDC data paints an even grimmer picture.

Drug overdose deaths involving xylazine:

• 2018: 102 deaths
• 2021: 3,468 deaths

That’s a 35-fold increase in just four years.

Between January 2019 and June 2022, the monthly percentage of fentanyl deaths that also involved xylazine jumped 276%—from 2.9% to 10.9%.

And nearly all xylazine deaths (97-100%) also involved fentanyl.

Where Is It Hitting Hardest? From Regional Problem to National Threat

Xylazine followed fentanyl’s trafficking routes, primarily through the Sinaloa and Jalisco cartels. It started in Puerto Rico in the 2000s, showed up in Philadelphia in the mid-2010s, then spread through the Northeast before moving south and west.

In 2021, the highest death rates were in:

• Mid-Atlantic region (Delaware, DC, Maryland, Pennsylvania, Virginia, West Virginia): 4.05 deaths per 100,000
• New England and New York/New Jersey: Also significantly elevated
• Midwest and South: Lower but rising fast
• West: Just beginning to see the wave

Between 2020 and 2021, xylazine-related deaths exploded:

• South: 1,127% increase (116 deaths → 1,423 deaths)
• Midwest: 516% increase
• Northeast: 103% increase
• West: 50% increase

Xylazine isn’t just a “fentanyl problem” either. It’s showing up in cocaine, heroin, and methamphetamine. This is a polysubstance crisis.

The Government’s Response: A Multi-Agency Battle

The U.S. government’s response to the xylazine crisis, while now robust and coordinated, was largely reactive, highlighting systemic weaknesses in the nation’s ability to detect and respond to emerging drug threats.

Early warnings from public health practitioners in Puerto Rico and Philadelphia in the preceding decade did not translate into a national-level response until the crisis had already spread across the country and the death toll was climbing exponentially.

First Warnings (2022-2023)

FDA (November 2022): Issued an alert to healthcare providers about xylazine’s risks, including that Narcan can’t reverse it and that it causes severe skin ulcers. In early 2023, the FDA issued an Import Alert allowing border agents to detain suspicious xylazine shipments while protecting the legitimate veterinary supply chain.

DEA (March 2023): Issued a Public Safety Alert warning Americans about “the widespread threat of fentanyl mixed with xylazine,” sharing the statistics about how prevalent it had become in seized drugs.

SAMHSA: Sent guidance to addiction treatment providers about managing xylazine withdrawal and treating the wounds.

The Historic Designation (April 2023)

On April 12, 2023, the White House Office of National Drug Control Policy did something unprecedented: officially designated fentanyl mixed with xylazine as an “emerging threat to the United States.”

First time ever using this authority.

This triggered the development of a comprehensive National Response Plan (released July 2023) built on six pillars:

1. Testing: Scale up xylazine testing in death investigations, law enforcement, and clinical settings
2. Data Collection: Create a centralized tracking system and public dashboard
3. Evidence-Based Prevention, Harm Reduction, and Treatment: Develop and share best practices for care
4. Supply Reduction: Disrupt the illicit xylazine supply chain
5. Scheduling: Evaluate placing xylazine under the Controlled Substances Act
6. Research: Better understand xylazine’s effects and develop new interventions

The plan set a concrete goal: achieve a 15% reduction in xylazine-positive overdose deaths in at least three of the four U.S. regions by 2025 (using 2022 as the baseline).

The Scheduling Debate

Here’s the problem: xylazine isn’t a controlled substance. That limits what the DEA can do. They can’t fully regulate its distribution, track it through their systems, or bring federal trafficking charges.

Congress is considering the Combating Illicit Xylazine Act (H.R. 1839/S. 993). It takes a novel approach:

• Classify xylazine as Schedule III—but only for illicit use
• Explicitly protect legitimate veterinary use
• Require DEA to track xylazine and report on diversion sources

The idea is to give law enforcement the tools they need without disrupting agriculture and veterinary medicine. If successful, this framework could set a precedent for handling future dual-use substances.

Staying Safe: Harm Reduction and Community Resources

The drug supply is unpredictable and dangerous. Here’s how to reduce your risk.

If Someone Overdoses

Signs of a xylazine-fentanyl overdose: unresponsive, very slow or stopped breathing, blue or gray skin, won’t wake up even when you shake them or rub their chest.

What to do:

1. Call 911 immediately. Tell them you suspect an overdose and that xylazine (“tranq”) may be involved. Professional medical help is essential because Narcan alone won’t be enough.
2. Give Narcan. Spray one dose in one nostril. Wait 2-3 minutes. If no response, give another dose. The fentanyl component is still the most immediate breathing threat, and Narcan can reverse that.
3. Do rescue breathing. This is critical for xylazine. Tilt their head back, lift their chin, pinch their nose, and give one slow breath every 5-6 seconds. Keep them oxygenated until help arrives.
4. Recovery position. If they start breathing on their own but stay unconscious, roll them on their side so they don’t choke if they vomit.

Most states have Good Samaritan laws protecting people who call 911 during an overdose from drug possession charges.

Reducing Your Risk

Test your drugs. Fentanyl and xylazine test strips are available. They’re not perfect, but they give you information. If you know xylazine is present, you can take extra precautions.

Never use alone. If something goes wrong, you need someone there who can help. If you don’t have someone, call the Never Use Alone Hotline: 1-800-484-3731. A trained volunteer stays on the phone with you while you use and calls emergency services if you become unresponsive. It’s free, confidential, and has saved lives.

Start low, go slow. Street drug potency varies wildly batch to batch. Try a small amount first to gauge the strength.

Taking Care of Wounds

Xylazine wounds start small—blisters, scabs, bruises—then get worse fast.

Get medical care immediately when you notice a wound. Early treatment matters.

Basic care: Keep wounds clean with soap and warm water. Pat dry. Cover with petroleum jelly and a clean bandage. Don’t use alcohol or peroxide (they damage tissue). Draw a circle around the wound with a marker so you can track whether it’s growing or shrinking.

Consider safer routes: Using sterile injection equipment every time, rotating injection sites, or switching to smoking or snorting may reduce wound risk.

Finding Help: National Resources

For those seeking help for substance use or looking for reliable information, several federal resources are available.

National Helplines and Treatment Locators

SAMHSA’s National Helpline: 1-800-662-HELP (4357): A free, confidential, 24/7 treatment referral and information service for individuals and families facing mental and substance use disorders.

FindTreatment.gov: A website run by SAMHSA that allows users to find substance use treatment facilities anywhere in the United States.

988 Suicide & Crisis Lifeline: Call or text 988 for immediate support for anyone experiencing a mental health or substance use crisis.

Trusted Information Sources

National Institute on Drug Abuse (NIDA): Provides comprehensive, science-based information on xylazine and other substances.

Centers for Disease Control and Prevention (CDC): Offers public health data, guidance, and resources on overdose prevention.

Drug Enforcement Administration (DEA): Publishes factsheets and public safety alerts on emerging drug threats.

The xylazine crisis represents a new and particularly dangerous evolution in America’s ongoing overdose epidemic. What began as an animal tranquilizer has become a national emergency, creating wounds that don’t heal, overdoses that don’t respond to naloxone, and withdrawal syndromes that resist standard treatment.

The government’s response, while comprehensive now, came after the crisis had already spread nationwide. This highlights the need for better early warning systems and the challenge of regulating dual-use substances that serve legitimate purposes while being diverted to deadly ends.

For individuals and communities, understanding xylazine means recognizing that the overdose crisis has fundamentally changed. Traditional harm reduction strategies must evolve to address naloxone-resistant overdoses and devastating skin wounds. The most important message remains unchanged: every life lost to this crisis is preventable with the right knowledge, resources, and response.

As the crisis continues to evolve, with new substances like medetomidine already appearing, the xylazine experience serves as both a cautionary tale and a blueprint for how America must adapt its public health and law enforcement responses to an increasingly complex and dangerous drug supply.

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