“Rhino Tranq” Hits US Streets as Drug Traffickers Up the Ante

The soul killers, the vile pushers of lethal illicit drugs, the evilest criminals on Earth have done it again.

Just when society was having some success with enforcement actions against the latest fatal cocktail to hit the market—a combination of the powerful anesthetic fentanyl and the animal tranquilizer xylazine—illicit chemists have come up with a new, more potent and even more lethal compound, combining fentanyl with the veterinary tranquilizer medetomidine, so deadly it’s left a crippling wave of mass overdoses in its brutal wake.

Philadelphia, for example, saw 160 hospitalizations of medetomidine and fentanyl overdoses in just four days, according to Alex Krotulski of NPS Discovery, an illicit drug tracking group.

“It’s critical to alert street users. They’re playing Russian roulette now with the drug supply.”

Cooked up in hidden, illicit drug kitchens—both south of the border and in the US—medetomidine makes fentanyl deadlier and is 10 to 20 times stronger than xylazine.

Medetomidine has gone international as well, found in Canada in samples analyzed by Toronto’s Drug Checking Service. Their report raised awareness of the alarming reality that drug users often have no idea what they are taking: “Medetomidine was found in samples expected to be fentanyl, alongside high-potency opioids, like fentanyl, fluorofentanyl and/or a methylfentanyl-related drug, as well as other central nervous system depressants, like benzodiazepine-related drugs and/or xylazine. The presence of medetomidine was not reported as being expected by those who submitted these samples to be checked.”

In other words, drug users who buy and shoot up have no idea whether their current “fix” contains only their usual fentanyl or a lethal combination of fentanyl and medetomidine. “It’s critical to alert street users,” Dr. Bertha Madras, Harvard drug researcher, said. “They’re playing Russian roulette now with the drug supply.”

“Patients are being cared for as we speak in emergency rooms,” said Krotulski. “These are very complex drug products. You’ve got fentanyl adulterated with xylazine that now also contains medetomidine.”

Even more frightening: Though EMTs and police have often saved victims of fentanyl overdoses by quick administration of the opioid reversal drug naloxone, it doesn’t work on medetomidine or xylazine.

On the street, the fentanyl/medetomidine combination is called “rhino tranq,” to indicate that its potency is much higher than the fentanyl/xylazine combo (that cocktail was merely nicknamed “tranq,” though it was certainly bad enough).

Both xylazine and medetomidine exhibit similar symptoms: heavy sedation, making users appear to be wandering the streets, bent over at the waist, confused and semi-conscious (at best); cardiac depression that can take pulse rates down to as low as 20 beats per minute, barely living (a resting heart rate is 60, and anything lower constitutes a dangerous condition known as bradycardia); respiratory depression; and, in the case of xylazine, severe skin sores that are highly difficult to heal.

“When an individual takes the medetomidine/fentanyl combination in ‘rhino tranq,’ they are at high risk of both their heart and breathing stopping and causing a sudden overdose death,” reported one Michigan addiction treatment provider.

The fact that medetomidine is now found as an adulterant in fentanyl twice as often as xylazine in Philadelphia means that the risk of drug users accidentally getting a “hot shot”—a surprisingly high-potency dose of a drug, typically containing an unexpected adulterant—is greater than ever.

Mass overdose incidents involving medetomidine have taken place in Philadelphia and Chicago, with overdoses also reported in Missouri, Colorado, California and Maryland.

“There is an almost endless supply of new psychoactive substances and there are literally thousands and thousands of drugs that can be made.”

“Recent mass overdose outbreaks in Philadelphia, Chicago and elsewhere have all been associated with fentanyl or heroin drug products containing medetomidine, as well as xylazine and/or other substances,” the Center for Forensic Science Research & Education reported.

Another serious problem with medetomidine is that withdrawal can be much more severe than other drugs—causing a rapid heart rate, blood pressure spikes, disorientation, restlessness, confusion and severe vomiting.

The one constant in the whole illegal drug mess is this: the bodies keep piling up. While the death rate dropped in 2024, there were still 87,000 overdose deaths that year. Before fentanyl and its adulterants became the rage, there were just 53,356 in 2015.

“The shift from plant-based drugs, like heroin and cocaine, to synthetic, chemical-based drugs, like fentanyl and methamphetamine, has resulted in the most dangerous and deadly drug crisis the United States has ever faced,” Anne Milgram, former head of the DEA, said.

The drug epidemic has evolved from prescription opioids to heroin to fentanyl to fentanyl with xylazine to fentanyl with medetomidine, with each step up the deadly ladder seeing the drugs become more and more potent, more and more lethal—and all with the body count rising.

Ironically, the increasing use of medetomidine as an additive could be caused by the US enforcement agencies’ crackdown on xylazine, making it harder to obtain that drug. “Law enforcement is trying harder and harder to crack down on xylazine,” Dr. Jeffrey Singer, drug expert with the Cato Institute, said. “If the drug trafficking organizations are interested in adding a sedative, they can always add medetomidine.”

And they have. We can count on them to continue coming up with new drug additives that will make illegal street drugs even stronger and harder to stop.

“There is an almost endless supply of new psychoactive substances and there are literally thousands and thousands of drugs that can be made,” Dr. Madras said.

So maybe enforcement is a hopeless effort in the war against drugs; stop one drug—even hundreds—and the cartels, the pushers and the evil chemists in their hidden laboratories can just come up with more.

Maybe it’s time to cut back on focusing on enforcement and, instead, start putting our efforts into stopping drug addiction where it starts—in other words, prevention.

Truth is the best weapon we’ve got. Get the truth about drugs out there—the bitter truth about the horrors and tragedies these substances cause—and use that truth to empower people, especially young people, to make the decision to stay clean.

If we lead with truth and prevention, then maybe—just maybe—this is a war that can be won.