The pipeline of deadly fentanyl into the U.S. may be drying up, experts say

This summer, Dan Ciccarone, a physician and street drug researcher at the University of California, San Francisco, sent a team to gather data on the city’s streets in areas where illicit fentanyl has been a killer for years. They found something unexpected.

“The fentanyl supply is drying up for some reason,” Ciccarone said. “Hang out on the streets, talk to people — the drugs are hard to find and more expensive.”

When street fentanyl began spreading in the American street drug supply beginning in 2012, most experts believed the deadly synthetic opioid was unstoppable. Fentanyl is cheap, easy to make and hugely profitable. The black market supply chain that feeds U.S. demand for the drug is operated by some of the most sophisticated and ruthless criminal gangs in the world.

But Ciccarone said that over the past six months, he began hearing from street drug experts around the U.S. who also were seeing significantly less fentanyl and fewer overdoses.

“I head from Ohio, I heard from West Virginia, and I heard from Maryland and Arizona, and they’re all telling me the same thing: some sort of supply shortage on the street,” he said.

There are skeptics, people who question this trend, but some of the top drug policy analysts in the U.S., as well as experts with close ties to street fentanyl markets, believe the data shows a major disruption in the deadly fentanyl supply chain.

“It’s a development that many drug policy experts would not have imagined,” said Vanda Felbab-Brown at the Brookings Institution, who studies international criminal organizations that make and smuggle fentanyl.

She said drug gangs appear to be trafficking less fentanyl and are also “adulterating” or weakening the potency of the fentanyl being sold. “Everyone has been caught by surprise by the extent of the adulteration of fentanyl,” Felbab-Brown said. “And even more significantly by claims in certain places in the U.S. that there is not enough fentanyl available.”

Researchers generally agree there has been an “unprecedented” drop in fentanyl purity in some parts of the United States. Labs that test street fentanyl are finding it cut or watered down far more aggressively, often with an industrial chemical known as BTMPS.

An industrial chemical mixed into fentanyl

“We’ve had samples that were just BTMPS and not any fentanyl,” said Nabarun Dasgupta, an addiction researcher based in North Carolina who tests fentanyl samples collected from illicit drug markets around the country.

Edward Sisco, a research chemist at the National Institute of Standards and Technology who helped analyze fentanyl samples, said it’s a mystery why drug gangs would use BTMPS in fentanyl mixtures. There’s no indication the substance causes users to get high.

“It’s commonly used to prevent UV degradation of plastics, and it has some other industrial uses as well,” Sisco said, adding that it appears the chemical is being added to fentanyl powders deliberately early in the supply chain, possibly in drug labs in Mexico.

“When something new comes into the drug market, it usually comes in one geographical location. It’s very uncharacteristic to see [BTMPS] show up all over the country at one time,” he said.

While BTMPS is considered toxic to humans, it doesn’t cause overdoses or immediate death.

Some drug policy experts believe these shifts in the fentanyl supply are factors in the sudden national decline in fentanyl-related deaths, which dropped by roughly 20% last year, according to the U.S. Drug Enforcement Administration.

Dennis Cauchon, a harm reduction activist in Ohio, believes that pattern is visible in his state, where fatal overdoses have fallen even faster in 2024, down by roughly a third. “If you look at the share of fentanyl in Ohio’s drug supply, you can predict how many deaths there will be,” Cauchon said. “So the real question is, why has fentanyl declined?”

This question is being fiercely debated by drug policy and addiction experts.

Are Mexican drug cartels and their Chinese partners finally feeling pressure?

Some analysts believe international pressure on Chinese companies that make fentanyl precursor chemicals may be a factor. Others think a global crackdown on Mexican drug cartels that smuggle fentanyl into the U.S. is finally affecting the black market supply chain.

“There were nearly 70,000 pounds of fentanyl seized along the Southwest [U.S.] border in the 24 months ending in August 2024,” said Jen Daskal, a deputy assistant to President Biden on the National Security Council who focuses on fentanyl policy. “That’s more fentanyl seized in the past two fiscal years than in the prior five years combined.”

Seizures are one part of the strategy. The U.S. has also steadily ramped up direct pressure on the Mexican cartels, attempting to seize fentanyl profits, arresting top Sinaloa leaders and gaining more cooperation from the Chinese and Mexican governments.

Daskal acknowledged that drug deaths remain unacceptably high in the U.S. but said the Biden administration’s fentanyl strategy is showing progress: “We’re seeing the effects in terms of lives saved.”

Last year, the cartels seemed to acknowledge the pressure. They issued public promises to curb fentanyl production and smuggling into the United States. The U.S Drug Enforcement Administration voiced skepticism about the gesture, calling it “a public relations stunt.”

But Felbab-Brown at Brookings now believes some kind of meaningful “disruptions to U.S. supply” may have occurred inside Mexico. She says the cartels may also hope to reduce law enforcement focus on their operations by deliberately weakening the potency of street fentanyl.

“It could be their decision at the wholesale supply level to be adulterating fentanyl to reduce mortality. If that is the case, that is still a significant accomplishment by U.S. law enforcement, shaping markets and behavior,” she said.

“We need to be real careful about being too optimistic”

Not everyone is convinced the reduction in fentanyl supply on America’s streets is meaningful. Dan Salter leads a federal task force targeting drug traffickers in Georgia, North Carolina and South Carolina.

Salter told NPR that there has been a big drop-off in the amount of fentanyl turning up in drug seizures in his part of the U.S. in 2024. “We’ve seized almost 75 kilograms of fentanyl this year so far,” he said. “In 2023, we seized 216 kilograms.”

But according to Salter, this is likely a temporary and modest supply disruption that’s unlikely to last: “I think we need to be real careful about being too optimistic.”

Rachel Winograd, a drug policy researcher at the University of Missouri-St. Louis, is also skeptical that disruptions to the fentanyl pipeline are causing the drop-off in drug deaths, which are down by 34% in Missouri.

“Drug seizures at the border and elsewhere did really ramp up in 2023,” she said. “But I do not think that has anything to do with the decrease, at least not here in Missouri.”

Winograd thinks other factors, including better addiction treatment and the spread of the drug overdose reversal medication naloxone are bigger factors saving lives.

Experts agree the U.S. street drug supply remains incredibly toxic and dangerous. Substances being used to adulterate fentanyl, including BTMPS and xylazine, a horse tranquilizer that’s also known as “tranq,” appear to cause fewer fatal overdoses but are still harmful to humans. Front-line harm reduction workers also fear the growing variability in fentanyl purity could put some users at risk as they try to manage their doses.

Haven Wheelock, who works on the street for an organization called Outside In in Portland, Ore., said the sudden shift in the fentanyl supply is causing some people experiencing addiction to seek help. “Could it be a motivating factor for folks to do something different in terms of seeking treatment? Absolutely. It could also lead to more risky behaviors,” she added.

Wheelock warned that some people in severe addiction could also wind up injecting fentanyl, rather than smoking it, a practice that is considered more dangerous.

Ciccarone, the street drug researcher in San Francisco, believes an overall drop in fentanyl availability and purity has slowed overdoses in a meaningful way, contributing to a 15% drop in drug deaths in his city so far this year.

“The only thing that could really explain this is a supply shock,” he said. “The fentanyl is drying up.”

Most experts interviewed by NPR agreed the drop in fentanyl supply is significant and widespread but said it will take months of research and more data to confirm whether the change will have a lasting impact.