A terrifying new drug has gained a foothold in major cities - and is capable of rotting away peoples' skin, leaving medics with no choice but to amputate.
Xylazine is a sedative used by vets on large animals - such as horses and cows - and has never been approved for human use.
For more than a decade, drug dealers have been cutting it with heroin to sell on the streets.
But now the substance - commonly known as tranq - has gained a following on its own.
Doctors dealing with those who take the drug have noted it rots peoples' skin where they inject it, with people finding sores and ulcers and - in the worst cases - face amputation of their limbs.
The worst cases have so far been reported in Philadelphia, although overdoses have also been found in San Francisco and Los Angeles.
Dr. Gary Tsai, the director of substance abuse prevention and control for the LA County Department of Public Health, told the LA Times: “It’s not that common yet, but similar to fentanyl, it was more prevalent in the East Coast and it’s moving west, this is something that’s concerning.
“The main concern is we're already amid the worst overdose crisis in history, nationally and locally.
"This would increase deaths from overdoses."
The Drug Enforcement Agency said in a report it is sometimes used on its own, but also combined with other drugs such as fentanyl, cocaine and heroin.
Its use started on the streets of Puerto Rico before being found in the United States.
A report by the DEA said: “The prevalence of xylazine is increasing, spreading beyond the traditional white-powder heroin markets in the northeastern United States where it has been seen for several years.
“Xylazine vials have been encountered at locations operating as local stash houses or in the homes of polydrug dealers, indicating the mixture with other drugs happens at the retail level, though it cannot be determined how frequently.
“Xylazine, reported as an adulterant in an increasing number of illicit drug mixtures, has also been detected in a growing number of overdose deaths.
“It is commonly encountered in combination with fentanyl but has also been detected in mixtures containing cocaine, heroin, and a variety of other drugs.
“However, xylazine is most frequently reported in combinations with two or more substances present.
“In addition to its presence in drug combinations, xylazine (often known as tranq) is used on its own, though this is less frequently reported.
“Limited scientific research has been conducted on the effects of xylazine on the human body.”
