Researchers in the United Kingdom have detected the presence of the powerful sedative xylazine in cannabis vapes and illicit pills taken to treat pain, insomnia and anxiety, putting people who use the tainted drugs at risk of overdose or other serious health consequences. The prevalence of xylazine has been growing since 2022, according to researchers at Kings College London, when the first overdose death from the drug in the U.K. was identified.
Xylazine, a powerful non-opioid sedative commonly used as a veterinary tranquilizer, has been found in the drug supply in the United States for years. It is frequently mixed with heroin or fentanyl and has been implicated in thousands of overdose deaths nationwide, according to data from the Centers for Disease Control and Prevention. Although it is commonly found in the illicit drug supply, xylazine has not been approved for use in humans by the U.S. Food and Drug Administration.
The drug is a powerful sedative that can cause overdose and death, often when mixed with other drugs. Additionally, injecting the drug can cause skin ulcers and resulting complications including infections that sometimes necessitate amputation.
Xylazine Found in Vapes and Illicit Pills
In the U.K., researchers have found xylazine in THC vapes and counterfeit prescription drugs including codeine, alprazolam (Xanax) and diazepam (Valium) tablets, according to a study published on Wednesday. The research identified xylazine in samples collected from 16 people in the U.K., including 11 who had died.
“Xylazine has already penetrated the U.K. illicit drug market and is not limited to heroin supplies. Urgent action is needed to protect both people who use heroin and the wider population of people who use drugs from its acute and chronic health harms,” the researchers wrote.
In nine of the 11 confirmed deaths, xylazine was found in combination with an opioid such as heroin or fentanyl. Researchers say the lack of such a combination in the remaining two deaths suggests that xylazine may have been part of an illicit tablet or vape.
“This is cause for alarm as a much wider population of people who use drugs beyond heroin users will be exposed to its harms,” said Dr. Caroline Copeland, senior author of the study, told The Guardian.
“We also know that most people who buy heroin will not intend to buy xylazine and this combination increases the risk of overdose,” Copeland added. “Xylazine was designated an ‘emerging threat’ to the United States and this public health threat is a growing concern for the U.K.”
Copeland added that the total number of deaths in the U.K. is probably even higher because xylazine stays in the body for only a short time. Since August 2023, the last death covered by the research, “we’ve had several more deaths so it is only continuing and increasing,” the researcher said.
Dr. Benjamin Caplan, M.D., the chief medical officer at cannabis consultations provider CED Clinic and the author of The Doctor-Approved Cannabis Handbook, says that the “discovery of xylazine in counterfeit codeine, diazepam (Valium) tablets, and recently within THC vapes — particularly those sourced from home-grown suppliers — is particularly troubling.”
“These counterfeit products, often look like products sold from reputable sources, and so they may appear safe, but in fact may pose a grave threat to unsuspecting consumers,” Caplan, who was not involved in the U.K. study, wrote in an email to High Times. “My professional experience includes dealing with the aftermath of such substances, including patients who have suffered or even lost loved ones to adulterated products that they purchased outside of regulated dispensaries, which are closely monitored to avoid any such contamination.”
A U.K. government spokesperson said that officials “are aware of the threat from xylazine and are determined to protect people from the threat posed by this drug and other illicit synthetic drugs.”
“We will not hesitate to act to keep the public safe,” the spokesperson said. “Following advice from the Advisory Council on the Misuse of Drugs, we intend to make xylazine a class C drug meaning anyone supplying this substance will face up to 14 years in prison, a fine or both.”
But study co-author Dr. Adam Holland, a co-chair of the drugs special interest group at the University of Bristol, said the increase in drug contamination and overdose deaths is a clear sign that punitive drug laws are not working.
“We need to expand the range of harm reduction interventions available for people who use drugs, including drug checking and overdose prevention centers, to give them the opportunities they need to stay safe,” Holland said.