Now Illinois' latest drug threat is attracting the attention of state lawmakers in Springfield.
Because it's not a federally controlled drug, there is new legislation in Springfield that would make misuse a crime.
RELATED: What is xylazine? Animal tranquilizer becoming more common in Chicago, suburban street drugs
Dr. Elisabeth Poorman, at UIC, talked about the toxic effects of Xylazine -- which has been used to dilute heroin and other illicit street drugs, many times unknowingly ingested by users.
"Because there's, of course, no quality control, no checking, you know, which is a thing -- a service that exists in many other countries that have are more successfully combating overdoses. But here, you don't really know what you're getting at all," Dr. Poorman said.
That poisoning of the illicit drug supply is resulting in hard to treat wounds, which is a mysterious flesh-eating fallout from xylazine.
At Chicago Recovery Alliance, there is hope and research now underway for test strips that could one day alert drug users to the presence of potentially deadly xylazine.
"It can create ulcers around the body, many times not related to injection site. Also, those wounds won't heal if the individual is still consuming xylazine. So, they remain as open wounds that can then become infected and, unfortunately, at times require amputation," said Taylor Wood, who runs the drug checking program for the outreach program.
As teams in UIC's Mobile Care Unit administer care to Chicago's drug using communities, Dr. Poorman worries the overdose problem is worsening.
RELATED: 'Drug soup' containing fentanyl, xylazine, other substances continues to fuel overdose deaths
"Xylazine is a great example of how bad our drug checking is and, you know, how little access people have to having any clue what exactly it is that they're using," she said.
Unlike cocaine, heroin and opioid pain meds that are all subject to federal criminal laws. Xylazine is not.
Illinois legislation introduced this month in the Senate would outlaw the manufacturer, delivery or possession of the animal tranquilizer for human use.
However, even laws don't address the humanity Dr. Poorman said is needed.
"People who use drugs are people who deserve our compassion and love, and that is the only way they are going to get better. If you instead say, you know, they're the scourge of the earth and we just got to stop, you know, drug use at whatever cost, then the consequence of that is clear. And we're seeing that right now with the worst overdose crisis in American history," Dr. Poorman said.
RELATED: Illinois overdoses are sky high, getting worse, federal public health investigators say
As the so-called zombie drug turns up in street drugs more frequently, experts fear overdoses will also undoubtedly increase. And those numbers are already astoundingly high.
With more than 100,000 people dead from ODs, 2022 is said to be the worst year ever for all drug overdoses in the U.S.