US Overdose Deaths Fell to About 70,000, but Animal Tranquilizers and Cychlorphine Are Spreading Through the Fentanyl Supply

Since overdose deaths peaked at roughly 110,000 Americans in 2022, the annual toll has fallen to about 70,000 last year. The drugs behind those deaths have kept changing. Two developments define the current phase: animal tranquilizers mixed into fentanyl, and a new opioid called cychlorphine that standard test strips cannot detect.

Fentanyl with a sedative on top

BBC correspondent Quentin Sommerville spent several days in Columbus, Ohio's Linden neighborhood with a 48-year-old Army veteran identified only as Mike. Mike has a 20-year-old opioid addiction. He smokes fentanyl in an alley, and a hit costs three or four dollars.

"This drug will damn near make you do anything, unfortunately," he told the BBC.

Fentanyl is entirely synthetic and 50 to 100 times more powerful than heroin. It is now often cut with xylazine and medetomidine, both synthetic animal tranquilizers that are referred to as "tranq." Mike named them himself: "Xylazine, and the one we can't pronounce."

The sedatives help prolong the fentanyl high. They also slow breathing, and naloxone does not work against them, the BBC reported. Xylazine also causes necrotic skin ulcers, wounds so deep they can reach the bone and are difficult to treat.

Sommerville wrote that the naloxone spray his team carries would likely not have worked on Mike, because he was not just smoking fentanyl. That is the reporter's assessment, not a clinical finding. It points to a real gap: naloxone, sold as Narcan, is a nasal spray that reverses opioid overdoses, and the BBC credits its widespread adoption with transforming the number of fatal overdoses and with saving tens of thousands of lives.

One of the drug kits Mike brought to a CDC-linked sampling program tested positive for medetomidine. Scott Sanders, who runs the recovery group Hope Dealers, described the supply plainly: "we think we are buying crack but we're not, we're buying a number of different things."

Cychlorphine moves west

The Drug Enforcement Administration has detected cychlorphine in the illicit drug supply. A notice from the Office of National Drug Control Policy says it may be 10 times more potent than fentanyl. The DEA reported its first detection in April 2024 in Florida.

A DEA advisory warns it often appears in counterfeit pills or fentanyl powder without the buyer's knowledge. Toronto's Drug Checking Service has detected it in counterfeit versions of Percocet, Dilaudid and OxyContin.

California's first recorded case was a 16-year-old San Francisco resident who fatally overdosed in April after taking a pill containing cychlorphine and other drugs. In September, San Francisco police arrested four people and seized more than 20,000 counterfeit pills in an investigation tied to the teen's death, according to a police department press release.

What the tools can and cannot do

A report from the American College of Medical Toxicology found that standard fentanyl test strips do not detect cychlorphine. A user who tests a pill, sees a negative result and takes it anyway could be swallowing a stronger opioid than the one the strip checks for.

Daryl Mangosing, a public health lecturer at Cal Poly, said that limitation needs to be communicated clearly "so people understand what a test result can and cannot tell them." His main concern, he told Mustang News, is that people "may be exposed to a potent opioid without knowing what they are taking."

On naloxone, the picture is unsettled. Mangosing said reversing a cychlorphine overdose may require multiple doses because of its high potency. He also pointed to recent evidence suggesting Narcan may reverse its effects, while noting that clinical knowledge of the drug remains limited.

So there are two different naloxone problems. Tranquilizers like xylazine and medetomidine are not opioids, so naloxone does not work against them. Cychlorphine is an opioid, so naloxone may work, possibly at higher or repeated doses.

Campuses start warning students

Cal Poly's Fraternity and Sorority Life office emailed students about cychlorphine and encouraged them to avoid mixing substances or using illicit substances alone. Alpha Chi Omega president Maile Marinchak said she wants everyone "informed, cautious and prepared to help if something happens."

Awareness is thin. Jonathan Desjardins-Wiggins, a Cal Poly software engineering sophomore, said he had not heard anyone around him talking about the drug.

Andre Sillas, Cal Poly's alcohol and other drug prevention education specialist, said there is currently no reliable way to predict how much Narcan it takes to reverse a cychlorphine overdose, which is why Campus Health & Wellbeing recommends students carry more than one dose. Its Overdose Prevention Kit includes two doses of Narcan, fentanyl test strips, a rescue breathing mask and educational resources.

The enforcement and treatment question

The San Francisco arrests show what policing can do once a death is traced to a pill supplier. Counterfeit pills made to look like prescription drugs put the risk on buyers who think they are taking something regulated.

The drop from 110,000 deaths to about 70,000 is real and worth acknowledging. The BBC's reporting also shows it has not ended the crisis in places like Linden, where users are buying cheap hits cut with sedatives.

The open question is how fast public health and law enforcement can adapt. Clinical knowledge of cychlorphine remains limited, standard test strips miss it, and Cal Poly's own prevention specialist says there is no reliable way to predict how much Narcan it takes to reverse an overdose. Early identification of new compounds and warnings like the ONDCP notice will matter only if they reach users before the next death does.