What You Need to Know About Xylazine in the Drug Supply


Mary Beth Campbell is a trained public health professional who also has a background in harm reduction, but this feature is not a substitute for advice or care provided by a licensed medical or health care professional. All information provided is current at the time of publication, but new information may arise.


Over the past year, many sensationalized media reports about a new “zombie drug” have arisen. The drug in question, xylazine (also known as “tranq” or “tranq dope”) has been named an “emerging threat” by the Biden-Harris administration and is found in the U.S. drug supply, usually in combination with fentanyl or other opioids. The zombie moniker (a term that has a fraught socio-political history) springs from the fact that xylazine is a sedative and its use can be associated with the development of concerning wounds. Unsurprisingly, such language has led to increased stigma around use of the drug. In order to effectively deal with the negative consequences of xylazine, it is important to have a clear understanding of what xylazine is, how it got into the drug supply, what its effects can be, and what measures should be taken to ensure that people remain safe and healthy.

What is Xylazine?

Xylazine is part of the class of drugs known as alpha-2-adrenergic agonists, which act as anti-hypertensives (lower blood pressure) and sedatives. Xylazine was first synthesized by Bayer Pharmaceutics in 1962. It was investigated for use in human clinical trials as an analgesic (pain reliever drug), anesthetic, and sleeping aid medication. The human clinical trials were stopped, however, when participants experienced severe hypotension (very low blood pressure) and central nervous system (CNS) depression. As such, xylazine is not approved for human use. It is, however, approved for use in non-human mammals (e.g., dogs, cats, horses, cattle, elk, deer) and is currently used as a tranquilizer in veterinary medicine. More specifically, it is used in veterinary medicine as a sedative, muscle relaxant, and analgesic (pain reliever), as well as in the treatment of tetanus. Its use in horses has led to it being given the street name Anestesia de Caballo” (Horse Anesthetic) in Puerto Rico, where it was first discovered in the street drug supply, specifically in the opioid supply.

Emergence of Xylazine in the U.S. Drug Supply

Xylazine was first reported as an additive in the drug supply in Puerto Rico in the early 2000s. It eventually made its way into the Philadelphia opioid supply around 2010, especially in the Kensington neighborhood. Philadelphia-based independent reporter and ethnographer Christopher Moraff recalls seeing reports of “sleep cut,” which he thinks was likely heroin and xylazine, on a now-defunct harm reduction forum in 2008. Moraff reports extensively on the drug supply in Philadelphia, and is embedded in the Kensington neighborhood. In 2019 he broke the story that xylazine was in most of the opioid supply in Philadelphia. Moraff believes that the Philadelphia drug market became saturated with xylazine in part because of the Air Bridge Scandal, in which people in Puerto Rico who were seeking treatment for their opioid use were sent to Pentecostal churches in Kensington with the promise of receiving treatment and care. Instead, these individuals found themselves stuck in unregulated treatment facilities, which collected their promised food stamps, money, and other government assistance. Many of these individuals wound up living in the streets or in squats in or around Kensington, without the resources and support they were promised. Because xylazine was so common in the Puerto Rican drug supply at that point, Moraff hypothesizes that some of these individuals brought cuts with xylazine with them to the United States and helped to introduce it to the Kensington market. Eventually, xylazine made its way into the drug supply in Florida and the East Coast, and now seems to have made its way south. Some of the xylazine supply appears to be diverted from veterinary pharmacies, while some of the supply is being imported from China. Drug testing services began around 2019, allowing people to have a better idea of what substances are in the street drug supply. According to Moraff, “everything has xylazine.”

When speaking with Moraff, he also emphasized the role that drug criminalization and police crackdowns of the Kensington open air drug markets have played in the rise of adulterants such as xylazine in the drug supply. “If you’re not going to regulate a market, the best thing is to leave it alone,” cautions Moraff. The crackdown on fentanyl also helped contribute to the rise in xylazine in the drug supply, both in Philadelphia and the U.S. in general. This is a pattern observed with drug prohibition: It leads to an unregulated drug supply that creates more, not fewer, deaths. “Really, safe supply is where it’s at,” states Moraff.

Xylazine in Louisiana

According to Claire Zagorski, a trained paramedic, graduate research assistant at UT Austin’s College of Pharmacy’s PhARM program (Pharmacy Addictions Research & Medicine), and expert on xylazine, Texas has confirmed xylazine in the drug supply as of 2022, and it is being observed more consistently in Houston, which is both on I-10 and is a port city. Per Zagorski, though, “Drug supply surveillance is really weak, and mostly for political reasons.” Zagorski is currently working on a study to understand the geospatial distribution of drugs in Texas, which would also have utility in Louisiana since there are no drug checking programs in the state at the time of this writing. As noted by Zagorski, “Both Houston and El Paso are in this study, so if [El Paso] and​ Houston have the same supply, then that suggests it’s an I-10 route, which yes—would suggest that Louisiana is getting the same [drug supply]. But Louisiana, [especially New Orleans], is also on the Gulf, so it’s possible there’s a sea transport situation.” Adds Zagorski, “This is one of the things we lose in the Drug War—the ability to clearly see what the hell is happening in terms of supply chain logistics, which is hugely important. The DEA probably knows, but they don’t share with us.”

Volunteers with Trystereo harm reduction collective in New Orleans have received reports of worsening wounds from participants at their weekly drop-ins over the past year; several individuals presented with wounds that looked like textbook xylazine-related wounds. Trystereo began distributing DanceSafe brand xylazine test strips (which are currently legal in Louisiana) in August, and has asked participants to let volunteers know if any of their drugs tested positive for xylazine, in order to better understand what the current drug supply looks like in New Orleans. Thus far, a handful of people have reported positive results after testing their opioids. Dr. Elyse Stevens, an internal medicine physician specializing in primary care and addiction medicine at University Medical Center New Orleans—who also does medical outreach at Trystereo’s weekly drop-ins with local medical aid group Freestanding Communities—notes that “It wasn’t until about 2022 that I personally started seeing wounds suspicious for xylazine exposure here in New Orleans. Then again, it is often difficult to tell because our patients often have many other comorbidities that can mimic xylazine wounds.”

Reports of xylazine in Louisiana are not restricted to New Orleans. In Alexandria (located in Rapides Parish in Central Louisiana), FRESH Works, the syringe service program (SSP) associated with Central Louisiana AIDS Support Services (CLASS), staff observed the first likely case of a xylazine-related wound in August 2022. According to Alex Stallings, FRESH Works’ Director of Health Education & Wellness, “Over the past six months, I have seen more people exhibiting wounds that are more than ordinary… even among people who have used opiates for a long time… and in places where people don’t normally inject.” FRESH Works started distributing xylazine test strips in mid-July, and Stallings estimates that roughly 20% of the test strips they have distributed are reported by participants as testing positive for the drug, though he notes that “this could still be an underrepresentation.”

A Harm Reduction Approach to Xylazine

Xylazine has not been approved for use in humans, and the doses that people who use drugs are exposed to are higher and more frequent than what might be used in veterinary medicine. It is most commonly found in combination with fentanyl or fentanyl analogues. Some people who use drugs report preferring the combination of fentanyl and xylazine. It is believed that this association with fentanyl is partly due to the fact that the xylazine “gives legs” to, or extends the effects of, fentanyl, which has a shorter duration than heroin. In addition, some people report seeking out xylazine, in combination with fentanyl or on its own, because the sedative effects of xylazine might help them sleep (sometimes known as “bedtime” shots) or for other personal reasons. Other people do not like the effects of xylazine at all. As with all things, it comes down to personal preference, and it is important to not shame or stigmatize the intentional or unintentional uses of this substance. Instead, it is crucial to understand its effects in order to ensure that anyone who might use this substance has the knowledge and resources available to remain safe.

The acute, or short-term, effects of xylazine use include extreme sedation, low blood pressure, slow heart rate, and weak or absent reflexes. Depending on the dose and a person’s physical health, xylazine use might lead to prolonged periods of unconsciousness during which people might end up in positions that could compromise their airways, as well as put them at risk for developing pressure ulcers, blood clots, compartment syndrome (a painful and dangerous condition caused by pressure buildup from internal bleeding or swelling of tissues), and/or rhabdomyolysis (a breakdown of muscle tissue that releases the muscle protein myoglobin into the blood, which can damage kidneys). This is, of course, an even bigger issue for people who are unhoused. Sleeping on hard surfaces, such as cement, can increase the risk for tissue damage. There are other risks to being sedated in public spaces for prolonged periods of time, of course, including the risks of nodding out on railroad tracks, streets, or sidewalks, as well as theft, physical assault, and sexual assault.

Harm reduction guidance for people using xylazine, or who suspect that there might be xylazine in their drug supply, is to test their drugs (when possible), sit or lie down when using, never use alone, and take turns when using drugs. Place padding under any bony body parts (e.g., ankles, shoulder, hips), as this is also important to reduce injury. “My messaging is to look out for people who are nodding strangely, or for a long time. Don’t let people nod on sidewalks or roads, roll people from side to side every two hours or so, and don’t let people nod in weird, uncomfortable positions. And look out for people—don’t let someone assault or harm a friend who’s nodding” advises Zagorski. And, of course, recognizing the signs of and responding to an overdose is also necessary.

There has been much discussion about xylazine’s role in overdoses. Since xylazine is not an opioid, the overdose reversal drug naloxone will not reverse its effects. However, it is extremely important to emphasize that xylazine is most commonly found in combination with fentanyl and other opioids, and naloxone should always be used if an opioid overdose is suspected. Media reporting on xylazine has led to the myth of “naloxone resistant overdoses,” which is untrue and could lead to people not receiving the care they need, as some people may believe that naloxone will not work and thus will not administer it. As always, it is imperative to follow standard overdose response protocol, to administer naloxone to anyone who is thought to have overdosed, and to administer rescue breathing between naloxone doses until the person starts to breathe on their own. Notes Zagorski, “Xylazine doesn’t stop breathing, or even slow it down all that much. It slows heart rate, dulls reflexes, and makes people very drowsy, up to being unconscious. All that is to say… don’t over-focus on xylazine! Give naloxone, and watch for a change… Once the naloxone is working, if the person is breathing but not waking up like you might expect, then stay with them, and consider calling for help if things seem wrong. There’s no antidote for xylazine available, so we just need to support people until their bodies can metabolize it.”

Louisiana has a standing order in place for pharmacies to provide individuals with naloxone without a prescription, and individuals with Medicaid can access the medicine for free at their local pharmacy. Naloxone, in both nasal and intramuscular form, is also available for free at SSPs, though it should be noted that priority at these programs is given to people who might have difficulty accessing naloxone at places other than SSPs due to stigma and other barriers.

Xylazine’s chronic (long-term) effects include anemia (the body doesn’t produce enough healthy red blood cells), dysglycemia (irregular blood sugar levels), and wound formation. The development of xylazine-related wounds is of particular concern. The exact mechanism of how xylazine wounds develop is not yet known; however, according to both Zagorski and Dr. Stevens, there is strong evidence that the drug causes blood vessels and nerves to over constrict, impeding blood flow; this lack of blood flow can lead to both tissue and nerve death. Xylazine wounds have been observed mostly in people who inject drugs, since the wounds are associated with breaks in the skin, developing first as small lesions on the extremities (arms, legs) at or near the sites of injection, missed injection sites, and/or other areas of the body with skin injury. The wounds might start as small red-purple blisters, and if they develop further, may range in size from small, open sores to large ulcers, chronic osteomyelitis (serious infection of the bone), or, if not treated, gangrene that could lead to limb loss. As the wounds heal, a thick, dark eschar (dead tissue that eventually sloughs off healthy skin after an injury) typically forms. Secondary bacterial infections are a major concern, especially for people who are experiencing homelessness.

Zagorski wants to emphasize: “Don’t panic, but keep your eyes open… the worst effects of xylazine are manageable​.” She adds, “The wounds are scary, but respond to wound care. We don’t know how they develop or why they look how they do, but we can still treat the problem in front of us.” Xylazine test strips are another important tool, as they allow people to determine what is in their supply. The current versions on the market are only approved to test opioids; this is not an issue at the moment, as xylazine is mostly found in combination with fentanyl. These test strips are available for purchase and are being distributed at certain SSPs; however, if you have the means to pay for them, these programs ask that you do so in order for them to prioritize the needs of their program participants.

It is worth noting that alternative modes of consumption, such as snorting, smoking, or boofing (rectal administration) may not help prevent xylazine wound formation. These modes of consumption have long been recommended harm reduction practices for people who inject drugs to prevent HIV, Hepatitis C (HCV), and soft tissue infection. However, Zagorski, Dr. Stevens, and Moraff all note that they have heard anecdotal evidence of wounds forming after people used drugs containing xylazine via these varying methods. “This is another research question we need answered. I don’t really know that I have specific advice on this, aside from don’t assume that not injecting is safer for wound avoidance. It can be safer for other reasons! But this probably isn’t one of them,” states Zagorski.

For people who inject drugs, using sterile syringes and other supplies, cleaning the area of injection with alcohol pads before injection, maintaining good vein health, and keeping an eye out for the formation of any wounds is important. It is advised that people not inject near or in the wound site, and to avoid scratching or picking at wounds as much as possible. According to guidance from the University of Pennsylvania, wounds should be kept clean with soap and water or saline solution, and avoid using hydrogen peroxide or isopropyl alcohol (rubbing alcohol), as those products will, respectively, slow healing and dry out the skin, causing further damage. Make sure the skin around the wound area is kept moisturized, and apply antibiotic ointment to affected skin only if an infection develops. The wounds should be dressed and covered, with dressings changed every one to two days, ideally. Of course, this could be a challenge for individuals experiencing homelessness or without access to medical supplies. As always, it is strongly advised that anyone who suspects that they might have a xylazine-related wound, or any large wound in general, to seek medical attention immediately. “To my knowledge, xylazine wounds can also often require surgical intervention, so… seek emergency medical assistance immediately… [Individuals] with underlying conditions like HIV, hepatitis B or C, cirrhosis, heart failure, kidney failure, or severe COPD are at especially high risk for spreading, severe, frequently fatal infections. These wounds must be taken especially seriously,” cautions Dr. Stevens. This is especially important if any of the following is observed: rapidly-spreading redness, heat, and/or pain at the wound site; foul odor; changes in color in the skin; black tissue; chunks of tissue falling off; underlying bones and/or tendons are visible; and systemic signs of infection (e.g., fever, chills, and sweats). Again, this can all be managed as long as people know what to look out for and when and where to seek help.

Of course, stigma from the medical system might pose a barrier to accessing wound care, along with the other barriers to medical services that exist in the United States. Dr. Stevens, who works tirelessly at her clinic and outreach work, notes, “My services are just not valued in the larger health care system because my patients are not valued as human beings.” Says Stallings: “You certainly can’t understate the negative experiences people have experienced in the health care industry as to why they are reluctant to return to routine wound care appointments, beyond the normal barriers that are there.” He adds, “Any time that anything is deemed a criminal behavior… it is a lot more difficult for people to seek the medical interventions they might need… Criminalization plays a large role in the health outcomes of people who use drugs.” Public health and medical professionals need to address this stigma and biases against people who use drugs, in themselves and in their colleagues. Knowing what the long-term implications of untreated wounds can be, treating people with dignity instead of stigmatizing them can literally mean the difference between life and death.

Looking Forward

Bipartisan efforts have been made to make xylazine a Schedule III drug under the Controlled Substances Act, a move that has been decried by groups such as the National Harm Reduction Coalition. Scheduling drugs, too, makes it more difficult to study them, which would impede efforts to better understand and develop treatment for xylazine-related wounds and other side effects. Zagorski notes, “Several of us are urging legislators and regulators to pump the brakes on [criminalization of xylazine]… Unfortunately, as we’re beginning to see, cracking down on xylazine has shown to be a good public relations move for politicians who want to score ‘tough on drugs’ points.” Though there are negative health effects associated with xylazine use, criminalization and prohibition have not and will not solve any problems but only create new ones, including an increasingly unstable street drug supply.

There is a need to legalize and implement drug checking programs throughout Louisiana and the rest of the country. Such programs, similar to what Moraff described in Philadelphia, would allow for better understanding of the landscape of the drug supply, as well as let people make informed decisions about their drug use and prevent adverse health outcomes, including overdoses and the effects that are being observed with xylazine. Until these programs are implemented in Louisiana, University of North Carolina Chapel Hill’s Street Drug Analysis Lab and DrugsData.org offer anonymous drug checking through the mail, for free or a small fee. Though the results may take a few days to receive, these services at least allow people to have a general idea of what is in the drug supply.

Harm reduction services also need to be expanded in general. These programs not only provide people with sterile supplies but are also an entry point to medical services and other resources, ranging from linkage to HIV and HCV treatment, medication-assisted treatment (MAT) for those who are interested, housing, and more. Presently, they are only legal in Orleans parish, East Baton Rouge parish, Alexandria, and Shreveport. “There needs to be so many more needle distributions throughout the city [and state]… In my clinic, I should be able to hand out needles without question… Pharmacies should be forced to sell them to anyone, as they are over the counter, but they refuse to sell to anyone they think looks like a ‘drug user,’” states Dr. Stevens. She adds, “There [also] needs to be easy access to free wound care supplies and education. We need to be out in way more places cleaning wounds and assessing the impact of xylazine.”


Nasal naloxone (brand name Narcan) is available for free at distribution sites across the state, which can be located via the Louisiana Office of Public Health Hub’s Harm Reduction Portal: louisianahealthhub.org/hrdhub.


Illustrations by Kate Lacour

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