“We don’t know whether xylazine is increasing the risk of overdose or reducing the risk of overdose,” said Dr. Lewis Nelson of Rutgers New Jersey Medical School, who advises federal regulators on drug safety.
“All we know is that there are a lot of people taking xylazine and a lot of them are dying, but it doesn’t mean that xylazine is doing it.”
In almost all cases, xylazine — a drug for sedating horses and other animals — is added to fentanyl, the potent opioid that can be lethal even in small amounts. Some users say the combination, dubbed “tranq” or “tranq dope,” gives a longer-lasting high, more like heroin, which has largely been replaced by fentanyl in U.S. drug markets.
Like other cutting agents, xylazine benefits dealers: It’s often cheaper and easier to get than fentanyl. Chinese websites sell a kilogram for $6 to $20, no prescription required. Chemicals used to produce fentanyl can cost $75 or more per kilogram.
“Nobody asked for xylazine in the drug supply,” said Sarah Laurel, founder of Savage Sisters, a Philadelphia outreach group. “Before anybody knew it, the community was chemically dependent on it. So now, yes, people do seek it out.”
Xylazine’s effects are easy to spot: users experience a lethargic, trance-like state and sometimes black out, exposing themselves to robbery or assault.
“It’s a delayed reaction, I could be walking down the street, it's 45 minutes later,” says Dominic Rodriguez, who is homeless and battling addiction. “Then I wake up, trying to piece together what happened.”
U.S. regulators approved xylazine in 1971 to sedate animals for surgery, dental procedures and handling purposes.
In humans, the drug can cause breathing and heart rates to drop. It’s also linked to severe skin ulcers and abscesses, which can lead to infections, rotting tissue and amputations. Experts disagree on the exact cause of the wounds, which are much deeper than those seen with other injectable drugs.
Naloxone, a medication used revive people who have stopped breathing, doesn’t reverse the effects of xylazine.
Officials describe the drug's toll in stark terms and statistics: Fatal overdoses involving xylazine increased more than 1,200% percent between 2018 and 2021. But that largely reflects increased testing, since most medical examiners weren’t looking for the drug until recently.
“What it is doing is making the deadliest drug we’ve ever seen, fentanyl, even deadlier,” Anne Milgram, head of the Drug Enforcement Administration, told attendees at a recent conference.
New Jersey Police Capt. Jason Piotrowski, who oversees the analysis of state drug data, said xylazine’s ability to extend users’ high may be a factor in why it's showing up less than expected in fatal overdoses.
“If xylazine is lasting longer and that’s why people are using it, then they’re not going to need as many doses,” he said. “So now their exposure to the more deadly fentanyl decreases.”