What is Tranq?
In 2024, xylazine was linked to 41 drug-related deaths across Britain, up from 17 the year before, and just one in 2022. The surge prompted the government to make xylazine a controlled substance in January 2025, but by then, the drug had already spread through the UK’s illicit drug supply. Known on the street as “Tranq,” xylazine is designed for sedating horses and cattle, and has never been approved for use in humans. With Tranq now appearing in heroin, fake prescription tablets, and even cannabis vapes, understanding what it is and the harm it can cause can help keep you or someone you know safe.
What is xylazine?
Xylazine is a sedative and painkiller used in veterinary medicine. It is typically given to large animals like horses, cattle, and deer to calm them before procedures.
Xylazine works by activating alpha-2 adrenergic receptors in the central nervous system, which suppresses brain activity. In animals, these effects are temporary and carefully controlled by a vet. In humans, with no established safe dose and no medical supervision, the effects can be unpredictable and dangerous.
Xylazine first emerged as a street drug in Puerto Rico in the early 2000s. From there, it spread to cities in the United States, particularly Philadelphia, where it became so common in the fentanyl supply that the combination was declared an “emerging threat” by the US government in 2023. Now, Tranq has reached the UK, and while deaths are still relatively low, they are climbing year on year.
Why is xylazine in the drug supply?
Xylazine is cheap and easy to obtain. For drug suppliers, adding Tranq to heroin or synthetic opioids like fentanyl extends the duration of the high, making their product seem stronger or better value.
Research published in 2024 found that xylazine had “penetrated the UK illicit drug market.” Up to August 2023, Tranq had been detected in 35 cases, including toxicology reports, drug testing services, and police seizures across Britain. There were sixteen cases where a person tested positive for xylazine. Eleven of those cases were fatal.
What makes the UK findings particularly concerning is where Tranq is turning up. While it is most commonly mixed with heroin and other opioids, the same study found xylazine in counterfeit prescription tablets, and even in THC vapes. This means that anyone buying drugs from unregulated sources could be exposed.
What are the dangers of Tranq?
Xylazine has many powerful and harmful effects on the body, and it can be lethal. Some of the biggest risks of Tranq include:
Xylazine overdose
There is a risk of xylazine overdose every time you use it, particularly as Tranq is often mixed with opioids. This is very dangerous because both xylazine and opioids can slow your heart rate and breathing, potentially leading to a fatal overdose.
When someone overdoses on a combination of xylazine and opioids, administering naloxone may reverse the opioid component, but breathing may not recover because of the Tranq. This is why xylazine-involved overdoses are particularly deadly, and why opioid users need to understand that the drug supply has changed.
The first xylazine-linked death in the UK, and the first outside North America, was a 43-year-old man from Solihull in May 2022. Since then, deaths have risen sharply. In almost all UK cases where full toxicology was available, xylazine was found alongside heroin or another strong opioid.
Sedation and related dangers
Xylazine is a powerful sedative, with effects that last far longer than most opioids. When someone takes Tranq, even unknowingly, the effects can include extreme drowsiness, slowed or shallow breathing, a dangerously low heart rate, low blood pressure, and hypothermia. Users may appear unresponsive for hours, which is why Tranq is sometimes called the “zombie drug.”
Other physical symptoms
Because xylazine affects the central nervous system differently from opioids, it also causes symptoms that opioids don’t, like blurred vision, disorientation, and difficulty walking. People may not realise they’ve taken xylazine until they experience effects that feel unfamiliar or last much longer than expected.
Serious skin damage
This is what really makes xylazine different from other addictive drugs. Xylazine causes vasoconstriction, which means it narrows blood vessels and reduces blood flow to surrounding tissue. Without an adequate blood supply, the tissue starts to die. This begins as discolouration or small blisters, then progresses to deep, necrotic ulcers filled with dead tissue that continue to grow.
These effects are systemic, so the damage can appear anywhere on the body, not just where the drug was injected. The ulcers are prone to serious bacterial infections and extremely difficult to treat, and in the worst cases, severe enough to require amputation. In a study from Puerto Rico, 38.5% of xylazine users had skin ulcers, compared to 6.8% of those who didn’t use it. In Philadelphia, which has seen the worst of the US xylazine crisis, hospitals have developed specialist protocols for what they now call “Tranq wounds”.
Xylazine withdrawal
Xylazine withdrawal can be very unpredictable, with symptoms that include severe anxiety, agitation, restlessness, insomnia, and dangerous seizures. To make matters worse, people withdrawing from xylazine-contaminated opioids are effectively withdrawing from multiple substances at once.
One US woman who recovered from xylazine addiction described the experience to LBC: “All detoxes are horrible, but with xylazine it was like an alcohol, fentanyl and benzodiazepines detox all at the same time. I was having seizures, and it was awful.”
Because of these risks, medical detox at a centre like the Providence Projects is strongly recommended. Trying to stop alone, without support, can be dangerous, and the severity of withdrawal can also lead many people to relapse.
How to reduce the risks of xylazine?
If you’ve lost control of your xylazine use, or you’re worried you may be using it without knowing, the best thing you can do is stop taking any drugs. The Providence Projects helps people quit all kinds of drugs, guiding our clients through every stage of recovery. If you are waiting to start treatment, or you’re supporting someone else who isn’t ready to quit, there are steps you can take to temporarily reduce the risks:
Never use drugs alone
If you overdose on xylazine or a mixture of substances, having someone nearby could save your life. Naloxone can help reverse the opioid part of the overdose, and they can call for emergency medical help if you lose consciousness or can’t breathe.
Look out for the signs of xylazine exposure
These include unusually prolonged sedation, unexplained wounds or skin discolouration, or an overdose that doesn’t respond fully to naloxone. If you notice any of these, the least you can do is try to source drugs somewhere safer while waiting to begin treatment.
Test drugs before using them
There aren’t a huge number of options for self-testing drugs, but xylazine test strips may be available from some harm reduction services. WEDINOS, a postal drug testing service run by Public Health Wales, will analyse samples and publish results online. However, neither option is perfect, and you can never really know for sure what is in street drugs.
As explained above, these are only minor safety measures. With Tranq and other dangerous substances now present in so much of Britain’s drug supply, you are risking your life every time you use.
Get help for addiction at the Providence Projects
If you’re struggling with drug addiction and want to stop, effective support is available. The Providence Projects’ drug detox and rehab programmes can help you safely withdraw from drugs, address the underlying reasons for your drug use, and work toward long-term recovery. If you’re concerned about your own drug use or worried about someone you care about, contact us today. Our team can discuss all your concerns and help you figure out what comes next.
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If you are looking for rehab to take your, or a loved ones, life back from addiction, look no further than Providence Projects. Reach out to us today to find out how we can help you or a loved one achieve long-term recovery.
(Click here to see works cited)
- Copeland, Caroline S., et al. “Broad Evidence of Xylazine in the UK Illicit Drug Market Beyond Heroin Supplies: Triangulating from Toxicology, Drug-Testing and Law Enforcement.” Addiction, vol. 119, no. 7, 2024, pp. 1301-1309, pubmed.ncbi.nlm.nih.gov/38593992/.
- GOV.UK. “Britain Working at Pace to Curb Rising Synthetic Drugs Threat.” Home Office, 15 Jan. 2025, gov.uk/government/news/britain-working-at-pace-to-curb-rising-synthetic-drugs-threat.
- LBC. “Deaths Linked to Flesh-Eating ‘Zombie Drug’ in Britain Triple in Last Year.” 22 Oct. 2025, lbc.co.uk/article/deaths-linked-flesh-eating-zombie-drug-5HjdFjn_2.
- Malayala, Srikrishna V., et al. “Xylazine-Induced Skin Ulcers in a Person Who Injects Drugs in Philadelphia, Pennsylvania, USA.” Cureus, vol. 14, no. 8, 2022, pmc.ncbi.nlm.nih.gov/articles/PMC9482722/.
- Reyes, Juan Carlos, et al. “The Emerging of Xylazine as a New Drug of Abuse and Its Health Consequences Among Drug Users in Puerto Rico.” Journal of Urban Health, vol. 89, no. 3, 2012, pp. 519-526, pmc.ncbi.nlm.nih.gov/articles/PMC3368046/.
- Rock, Kirsten L., et al. “The First Drug-Related Death Associated with Xylazine Use in the UK and Europe.” Journal of Forensic and Legal Medicine, vol. 97, 2023, sciencedirect.com/science/article/pii/S1752928X23000604.
- Warp, Peyton V., et al. “A Confirmed Case of Xylazine-Induced Skin Ulcers in a Person Who Injects Drugs in Miami, Florida, USA.” Harm Reduction Journal, vol. 21, no. 64, 2024, harmreductionjournal.biomedcentral.com/articles/10.1186/s12954-024-00978-z.