A tranquilizer commonly referred to as a “zombie drug” is being manufactured and smuggled across the U.S. southern border, according to a doctor who has spent years studying it. 

The drug xylazine, known as “tranq” in street lingo, is used as a tranquilizer by veterinarians. 

In the 2010s, the drug made its way to the streets almost exclusively by being stolen from veterinarians and was particularly prevalent on the East Coast. Now, it is being manufactured and coming from abroad, and its footprint could dramatically scale. 

“There’s evidence of it being imported into the U.S. through the southern border and also evidence of diversion of domestic veterinary supply,” Dr. Joseph Friedman, who has studied xylazine for years, told Fox News Digital.

NAVY DEPLOYS ADDITIONAL WARSHIP TO CURB ILLEGAL IMMIGRATION, DRUG SMUGGLING AT THE SOUTHERN BORDER

While Friedman says he doesn’t know what proportion of the drug is being smuggled versus stolen from veterinarians in the U.S., his latest study, published in January, shows the drug’s prevalence in Tijuana and southern California. 

“Our study showed it being mixed into fentanyl in Tijuana, Mexico, specifically, and it’s also present in San Diego and southern California more broadly,” he said. 

“The arrival of xylazine-fentanyl co-use to the North American overdose crisis has been highly notable, and xylazine has been identified as an emerging threat by the government of the U.S., Chile, by the Organization of American States, and more recently by Mexico,” the study says.

DEM LOOKS TO CODIFY NEW AG BONDI’S DESIRED CRACKDOWN ON ‘ZOMBIE DRUG’ XYLAZINE

The drug leaves users in a “zombie-like” state as it constricts blood vessels and cuts off oxygen flow to the body, causing abscesses that rot the flesh. 

The drug is also uniquely dangerous because it does not respond to naloxone, which is used to counteract opioid overdoses, and when the drug is detected, it is almost always detected with the deadly synthetic opioid fentanyl. 

“It’s almost exclusively used together with fentanyl to augment it, almost never by itself,” Friedman said. 

In fact, in more than 98% of xylazine detections, it is detected alongside fentanyl, according to a 2022 study he published.

FDA RESTRICTING IMPORTS OF XYLAZINE OVER OVERDOSE CONCERNS

That study showed xylazine presence in overdose deaths had jumped from 3.6% in 2015 to 6.7% in 2020. 

A Centers for Disease Control and Prevention study published in 2022 concluded that xylazine prevalence in opioid deaths had increased from 2.9% in January 2019 to 10.9% in June 2022.

Fox News Digital reached out to U.S. Customs and Border Protection. 

The Drug Enforcement Agency (DEA) issued a public safety alert about the drug in 2023.

“Xylazine is making the deadliest drug threat our country has ever faced, fentanyl, even deadlier,” the DEA said at the time. “The DEA has seized xylazine and fentanyl mixtures in 48 of 50 states. The DEA Laboratory System is reporting that in 2022, approximately 23% of fentanyl powder and 7% of fentanyl pills seized by the DEA contained xylazine.”

Fox News’ Melissa Rudy contributed to this report.