FDA Takes Action on Xylazine, Animal Tranquilizer Abused as a Skin-Rotting Drug

Police tape blocks a street where a person was shot in a drug related event in Philadelphia, Pa., on July 19, 2021. Spencer Platt/Getty Images

The U.S. Food and Drug Administration (FDA) on Tuesday said it has moved to restrict the illicit import of xylazine, a veterinary tranquilizer that is increasingly making its way across the nation as a street drug.

Xylazine is the active ingredient in a potent animal drug widely used to sedate dogs, cats, as well as large animals like horses and deer. The drug has never been approved by the FDA for use in humans, as it may cause serious and life-threatening side effects to the human body, including severe skin wounds and rotting tissue.

Citing a growing number of reports of xylazine being found in overdose deaths, the FDA on Tuesday issued an import alert, allowing agents to detain shipments of drugs containing xylazine, both finished product and substances used to make it, that appear to be adulterated or misbranded.

The federal agency said this action is meant to prevent xylazine from entering the market for illicit purposes, while still making the drug available for veterinarians who legitimately use it.

“It has been identified as a contaminant found in combination with opioids such as illicit fentanyl and in combination with other illicit products that contain stimulants such as methamphetamine and cocaine,” the FDA said in a statement, noting that people who use those drugs may not know of xylazine’s presence in what they are using.

“While xylazine is not an opioid, it is dangerous because it can depress breathing, blood pressure, heart rate, and body temperature to critical levels,” it continued. “Additionally, people who inject drugs containing xylazine can develop severe skin wounds and patches of dead and rotting tissue that easily become infected and, if left untreated, may lead to amputation.”

Xylazine, often sold under the street name “tranq,” has been found in overdose deaths across the country. According to the San Francisco Department of Public Health, tranq was detected in four out of 145 overdose victims tested in the city between Dec. 1, 2022, and Jan. 15. All four of the cases also involved fentanyl.

In an alert (pdf) issued last November, the FDA said health professionals should be aware that naloxone—a medication that rapidly reverses an opioid overdose—may not reverse the toxic effects of xylazine, which is not an opioid.

“Healthcare professionals who manage opioid overdoses should consider xylazine exposure if patients are not responding as expected when naloxone is administered,” the agency warned.

While reversal agents like yohimbine hydrochloride and tolazoline hydrochloride are regularly used in veterinary medicine, the FDA said they should not be used to treat xylazine-involved overdoses, since they are neither safe nor effective in humans.

In the meantime, the FDA said it is collaborating with federal, state, and local partners to investigate xylazine-related criminal activities, including online and in-person conduct.