Canada's fentanyl czar warns of newer, more lethal synthetic opioids

WASHINGTON – Canada’s "fentanyl czar" warns that newer, stronger and even more lethal synthetic opioids than fentanyl are increasingly showing up on both sides of the U.S. border and jeopardizing gains made in the joint U.S.-Canada anti-drug fight.

Kevin Brosseau − whose official title is Commissioner in Canada’s Fight Against Fentanyl and is the counterpart to the U.S. "drug czar" − said in an exclusive and wide-ranging interview with USA TODAY that nitazene and similar chemical compounds, in particular, have spurred the Ottawa government to ramp up work with partners around the world. They're working together to raise awareness of these new threats, to eliminate the precursor chemicals used to make them, and to combat the transnational organized crime syndicates peddling them, he said.

"I could have never predicted in the '90s, as I was dealing with heroin overdoses, that … new synthetics would be completely dominating, and they’ve essentially blown up the North American drug market," Brosseau said.

"That’s why I’m working with other countries, whether it’s in China, in India, with our G7 partners, so that we’re aware of what’s coming around the corner," Brosseau said. "Because if (fentanyl) has been this deadly, what’s next, right?"

Brosseau is concerned that these synthetic opioids are already causing an unknown number of fatal overdoses that aren't being fully counted because they're mixed in with fentanyl and other drugs that have been in circulation for years, if not decades. And clever chemists keep changing the laboratory-made formulas, he said, "with new and emerging chemicals that are coming around the corner" all the time.

Nitazene, for example, can be 10 times − or even 40 times − more powerful than fentanyl, which in turn can be 50 times more powerful than heroin. And because it’s made in a lab, unlike heroin that comes from cultivated poppy plants, traffickers can cook up large batches of it at relatively little cost and in labs away from the prying eyes of law enforcement.

A longtime counternarcotics official with the Royal Canadian Mounted Police, Brosseau said Canada-U.S. cooperation has helped both countries lower their respective fatal fentanyl overdoses by 20% in recent years – but that traffickers have adapted by manufacturing these other synthetic opioids.

The more powerful ones, like nitazene, are often mixed in with fentanyl and other drugs to make them stronger and more alluring to users, he told USA TODAY.

Brosseau has been the fentanyl czar since February 2025, after serving as the deputy national security and intelligence adviser to the prime minister. In March, he was given the additional role as Canada’s senior associate deputy minister of national defense.

Brosseau has met in recent months with his U.S. counterpart, Sara Carter, the director of the White House Office of National Drug Control Policy. In a statement to USA TODAY, ONDCP said Carter was not available for an interview and that, while it could not comment on details, “We are working closely with our Canadian counterparts.”

In the past, President Donald Trump has been critical of Canada's efforts to stem the flow of fentanyl into the United States, even pledging to enact stiff tariffs against the U.S. neighbors to the north – and south – until Canada and Mexico did more to prevent it.

Brosseau said U.S. counternarcotics officials have praised Canada for their aggressive efforts to fight fentanyl and other opioids – and that, despite some White House remarks, there is virtually no significant amount of the drugs going south into the U.S. at the northern border.

Nitazene 'significantly more powerful than fentanyl'

Nitazene, which is technically an entire class of highly potent synthetic opioids, is often mixed into heroin, fentanyl and counterfeit prescription pills to make them stronger and more addictive, according to the U.S. Drug Enforcement Administration.

Nitazenes were actually developed in the 1950s and never approved for medical use in the U.S. due to safety concerns, according to Kurt Larson, founder of the Safe & Sober anti-drug group and a Missouri attorney.

And while the medical community rejected the compounds, today’s illicit drug manufacturers have revived nitazenes in a far more concentrated and hazardous form.

"All they care about is maximizing their profits, not the loss of human life that comes with it − until someone stops them," Larson told USA TODAY.

On May 12, the DEA echoed Brosseau’s concerns, issuing a Public Safety Advisory about the "heightened threat" posed by fentanyl mixed with emerging synthetic drugs like nitazenes, xylazine, cychlorphine and medetomidine.

"These combinations are making an already deadly drug supply even more unpredictable and lethal," the DEA said.

The DEA said new nitazenes tend to be introduced when regulatory actions, enforcement and drug scheduling put pressure on existing analogues, including fentanyl. The U.S. drug agency has reported 22 unique nitazenes compounds since 2020, and warned that "these emerging synthetic drugs can be significantly more powerful than fentanyl and greatly increase the risk of suffering a fatal overdose."

Brosseau said that for the most part, fentanyl and other synthetic opioid compounds are being packaged and sold to recreational users in pill form.

"The other worry, and the part that I work a lot with industry about, is vaping," Brosseau said. "Young people think they’re vaping marijuana or cannabis or something more inert, and in fact, it’s being laced with an opioid because it’s addictive."

"Because that’s the business model; it makes you hook somebody, it’s stronger. They want more, right?" he said. "That's why this can’t be only about decriminalization and harm reduction techniques. That’s all great. But at the same time, we need to be holding people to account, and show that there are consequences for those who are willing to deal and distribute these products."

Larson said that nitazenes pose an urgent threat, especially among young people, because of the prevalence in marijuana vapes, counterfeit painkiller pills and other illicit powders like heroin – usually without the user knowing it.

He cited a March 24 Health Advisory from the Missouri Department of Health and Senior Services that said a state school wastewater testing pilot program detected nitazenes in 26 of 37 participating schools.

The latest evolution in the synthetic opioid trade

Brosseau said he first learned about synthetic opioids as a Royal Canadian Mounted Police commander in Winnipeg, Manitoba, in 2015, when addicts were stealing fentanyl patches from pharmacies.

Decades earlier, heroin was pervasive on Canadian and U.S. streets, he said.

Over time, the advent of lab-made synthetic opioids has made heroin almost non-existent in some parts of Canada, he said.

"Now the synthetic opioids can be found anywhere, and there’s such demand," he said. "It's so addictive and the lethality is such that it deserves the attention from law enforcement that it needs."It's also harder to catch synthetic opioid traffickers, Brosseau said, because they don't operate out in the open.

"We're no longer burning down poppy fields or coca plantations," to eradicate the heroin and cocaine trade, Brosseau said.

Now, he said, authorities are finding everything from industrial-scale manufacturers for transnational drug cartels to "artisanal" dealers that make nitazene and other synthetic opioids in their basements and press them into pills and whatever other form they think users will buy.

A partnership built on the 'War on Terrorism'

Brosseau said the U.S.-Canada partnership to combat synthetic opioids is modeled on the two countries’ cooperation on terrorist threats in the aftermath of the Sept. 11. 2001, attacks on New York and Washington.

"We recognize the shared threat, the major implications it has on a North American and hemispheric perspective, and that partnering and having those information flows back and forth is how we’re actually going to tackle this," Brosseau said.

Much progress has been made, he said, "but a lot more needs to be done, and we can’t let our foot off the gas."

This story has been updated.