“Zombie Drug:” What It Is and How It Affects People

Xylazine, a veterinary tranquilizer increasingly found in the opioid supply, is raising serious health concerns in communities across the country. Often referred to as the “zombie drug” in media reports because of its intense sedating effects, xylazine creates additional risks for people who use drugs—especially since typical overdose reversal medications don’t work on this substance. Its rise is tied to the ongoing opioid crisis, creating challenges for public health and increasing risks for those who use fentanyl and other opioids.  

While some media outlets have sensationalized its effects with dramatic nicknames, understanding the real risks—and how to reduce harm—is key to supporting people who might be exposed to this substance. Understanding what xylazine is, how it affects people, and where to find help can save lives.

A Note on Language and Stigma 

Addiction researchers point out that sensationalizing xylazine by portraying users as zombies only adds to the trauma that people struggling with addiction are already facing:

Zombies are cinematically depicted as soulless, dangerous, and required to be killed off entirely for public safety, making the ‘zombie’ analogy especially grave amid the fatal overdose crisis. Xylazine is called the ‘zombie drug’ due to its heavy sedative effect and associated severely infected skin ulcers. We surmise that wide-scale media framing of xylazine as the “zombie drug” has increased stigmas¹ onto people who use drugs as their likening to zombies reifies subhuman status.

The skin ulcers caused by xylazine require specialized medical care, which people are less likely to seek if stigma is a barrier. “Xylazine’s proliferation in the illicit drug market will likely increase infected ulcers needing medical attention. People who use drugs are often reluctant to seek medical care due to experiences of medically institutionalized stigma,” say authors of a paper on media framing around xylazine.¹ Instead, we should focus on addressing these concerns with compassion and care. 

Learn more about undoing stigmatizing language in our interview with Licensed Professional Counselor Andrew J. Schreier.

What Is the “Zombie Drug?”

Also known as “tranq,” xylazine is a powerful sedative used by veterinarians to calm large animals like horses during medical procedures. Recently, it’s been showing up in street drugs, often mixed with opioids like fentanyl without users’ knowledge. Public health officials are concerned because many people don’t realize they’re being exposed to this additional substance. According to the DEA, xylazine is “commonly encountered in combination with fentanyl² but has also been detected in mixtures containing cocaine, heroin, and a variety of other drugs.” People sometimes use tranq on its own, but this is less common. 

Increasing Prevalence 

Tranq is increasingly found in the illicit drug supply. Because it’s most often mixed with opioids like fentanyl, its rise across the U.S. “appears to be following the same path as fentanyl.”³ It first appeared in 2006 and gained popularity in the mid-2010s, starting in Philadelphia and then spreading throughout the East Coast, to the South, and eventually to the Western U.S. 

James Sherman, director of men’s programs at Savage Sisters Recovery Center in Philadelphia, describes the extent to which tranq has taken over the local drug scene: 

[Before] I got sober, it was still kind of a decision. It was like, ‘Go to this block if you would like tranq, go to that block if you want fentanyl.’ And that’s just completely changed. You don’t have a choice anymore.

DEA lab analysis shows xylazine’s increase in the drug supply by region between 2020–2021:

• Northeast: 103%
• South: 1,127%
• Midwest: 516%
• West: 750%

Xylazine use now extends beyond borders. In early 2024, Mexico raised concerns about the presence of tranq⁴ in states bordering the U.S., issuing a warning “for health personnel and first responders in Mexican border cities for possible adulteration of heroin and fentanyl with Xylazine.” Public Health Scotland also sounded an alarm in early 2024 following a wave of xylazine-related overdose deaths.⁵

Why Xylazine Use Is on the Rise

A few factors contribute to tranq’s popularity in already opioid-addicted regions:

Accessibility

Unlike many other drugs, xylazine isn’t classified as a controlled substance⁶ in most places. Because it can be purchased legally for veterinary use, “anyone with a vet’s license has access to it, and it can be ordered online,” says emergency department physician Carolyn Barber, M.D. While this makes sense for its intended medical purpose, it also means there’s less oversight over its distribution and use.

Affordability

The low cost of xylazine¹ has led to its increased presence in the drug supply. According to the DEA, “a kilogram of xylazine powder can be purchased online from Chinese suppliers with common prices ranging from $6-$20 U.S. dollars per kilogram.” Drug makers often add it to opioids because it has similar sedating effects, allowing them to use less of more expensive substances while providing a similar high. 

Duration of Effects 

Some people seek out xylazine-containing drugs specifically because the effects last longer than opioids alone. But this extended high also means increased risks, especially since xylazine can’t be reversed by naloxone and may require different medical responses in the event of an overdose.

Effects of Xylazine

Xylazine can affect your health in serious ways, and it’s important to know when to seek medical care. Even if you’re not ready to stop using drugs completely, healthcare providers can help treat these conditions and prevent them from getting worse.

Short-Term Effects

When someone is exposed to xylazine, whether they know it’s present in their supply or not, they might experience several effects:

• Intense drowsiness that makes it hard to stay awake
• Difficulty focusing or thinking clearly
• Problems with coordination and movement
• Confusion about time and surroundings

• Severely slowed breathing, which becomes especially dangerous when combined with opioids
• Dangerously low blood pressure
• Reduced body temperature
• Slowed heart rate

Long-Term Effects

Effects on Physical Health 

• Blurred vision
• Dangerously low blood pressure
• Slowed breathing
• Changes in heart rate
• High blood sugar levels
• Problems with balance and coordination

Skin and Tissue Concerns 

One of the most noticeable effects of xylazine exposure is its impact on skin and tissue health. Even brief exposure can cause wounds that:

• Appear suddenly and get worse quickly
• Often show up on arms and legs
• Can be very painful
• Need specialized medical care to heal properly
• May get infected if left untreated

Healthcare providers are learning more about how to treat these wounds effectively, and many hospitals now have special wound care teams who understand how to help. The sooner you get care, the better chance you have of preventing serious complications.

Getting Care 

If you notice any wounds or skin changes:

• Don’t wait to get them checked out
• Be honest with medical professionals about possible xylazine exposure so they can provide the right treatment
• Follow up with wound care appointments even if you’re still using
• Know that you deserve care regardless of your current situation

Healthcare providers increasingly understand these issues and want to help prevent serious complications. Many communities now have specialized wound care services that work with people who use drugs and provide care without judgment.

Overdose Risks

The combination of xylazine and opioids—both dangerous drugs in their own right—poses serious overdose risks. Xylazine amplifies the respiratory-depressant effects of opioids, making it easier to stop breathing entirely. Emergency responders often struggle to revive people who overdose on this drug, as opioid-reversal drugs like naloxone do not affect xylazine. Barber explains the risks this poses for people who use street opioids: 

Because xylazine is a sedative and not an opioid,⁶ overdose reversal medications like Narcan don’t address the drug’s major risks, which include dangerously lowering users’ blood pressure, heart rates and respirations. Those who ingest tranq as part of a fentanyl dose often lapse into hours-long blackouts; by the time they rouse themselves, the effects of the high have worn off, and the desperation for a new dose begins. The CDC still recommends the use of Narcan in suspected intoxications involving xylazine, because it’s so often combined with opioids like fentanyl and heroin.

The numbers are concerning, but fatal overdoses from tranq are likely severely underestimated. Testing processes for xylazine are inconsistent⁶ across the U.S. and can even vary within one state. “Many jurisdictions either don’t test for xylazine or only do so when no other drug has been implicated in death,” says Chelsea Shover, an epidemiologist at UCLA. “The latter almost never happens with xylazine, so there are probably many deaths that don’t get sent out for further testing because the initial toxicology has identified fentanyl or something else. It is expensive to test for extra or non-standard drugs, and many labs are very resource-constrained.”

Xylazine Vaccine

While authorities in the U.S. have started to grasp the seriousness of this crisis, they didn’t fully understand its breadth and depth due to a lack of accurate data. It is, however, clear that an antidote is urgently needed—which is why scientists are developing a vaccine to block xylazine’s toxic effects.⁷ So far, the vaccine has been tested on animals with promising results, say chemical biologists at Scripps Research.