Street drug concoctions are ever-changing. And as of late, there’s a lot less fentanyl in folks’ fentanyl.
But there’s more xylazine, a veterinary tranquilizer that can lead to hard-to-heal wounds (and does not respond to the overdose-reverser Narcan because it is not an opiate).
There are also more nitazenes and orphines, synthetic opioids that can be significantly more potent than fentanyl (which is far more potent than morphine) — or not.
There’s more medetomidine, a veterinary tranquilizer oft referred to as “rhino tranq.” It can lead to hallucinations and immobility and, like xylazine, it’s unfazed by Narcan.
There’s more BTMPS, a plasticizer with a fishy smell that can gum up and cause irritation at injection sites, and in nasal passages if snorted, and in lungs if smoked. Testing found that some samples of street-sold fentanyl were up to a quarter BTMPS. “That’s a lot of plastic in your body,” said Traci C. Green, a research scientist at Brandeis and Brown universities.
Green was among the researchers at the American Society of Addiction Medicine’s recent conference in San Diego, updating clinicians on the latest “cuts” in fentanyl products trading on the streets.
It’s “whack-a-mole” with additives, she said, and inconsistencies in purity and potency affect withdrawal, tolerance and overdose risk.
“The drug supply has never been more dangerous and unpredictable,” said Dr. Timothy J. Wiegand, moderator at the “Understanding the Evolving Drug Landscape: From Epidemiology to Clinical Practice” session.
Parents, talk to your kids. Again.
In just six months of 2024,”rhino tranq” positivity in samples soared from 29% to 87%, while xylazine positivity plunged from 97% to 42%, said Dr. Joseph D’Orazio, associate professor of emergency medicine at the Cooper Medical School of Rowan University in New Jersey.
Medetomidine withdrawal is more severe than xylazine withdrawal, and heartbeats have been known to fall to just 30 beats per minute, he said.
Then there’s kratom, the plant from Southeast Asia. Its most potent derivative, 7-OH, has been called “gas station heroin” and “legal morphine.” It is banned in California and many other states, but is still readily available, over-the-counter, at many vape shops. Doctors warn that it’s highly addictive and can be very difficult to treat.
Despite all this, there are some encouraging signs on the horizon, Green said. Adolescents are experimenting with drugs at much lower rates than they used to, and overdose deaths have dropped significantly.
There were about 112,000 overdose deaths in 2023, and just 70,000 in 2025, according to data from the U.S. Centers for Disease Control. That’s a plunge of some 38%.
Why, exactly?
A paper published in January in the journal Science suggests that the answer is China. Government crackdowns on the chemicals used to manufacture street fentanyl closed hundreds of suppliers and arrested hundreds of people in 2023, when the decline in overdose deaths began.
That may have resulted in the substitution of less-lethal drugs, like xylazine, to the mix, researchers said.
Supply changes are a synthetic era reality, Green said, and “polysubstance use” occurs whether people intend it or not. In the West, older people who use drugs continue to see high overdoses, and young people who dabble face an increased overdose risk due to infrequent use and the drugs’ high potency.
Community drug checking — a harm-reduction tool gaining ground in many eastern states — can be helpful for care and prevention.
“StreetCheck” is online at https://info.streetcheck.org/. “As the street drug supply is unregulated and unpredictable, community drug checking helps people who use drugs better understand what substances are in the drugs they use,” its mission statement says.
“The vision of StreetCheck streamlines community illicit drug sample collection through a free, web-based platform and app service, speeds up analysis of the samples, and makes it easier to communicate results back. The project began in Massachusetts, connects sites in the Northeast, and welcomes community partners throughout the country.”
Shall we, California?