Why were toxic drug deaths in B.C. down 21% in 2025?

New research using drug-checking results could provide an insight into why toxic drug death tolls have been on a downward trend for two years now in B.C.

But scientists and officials say there are likely multiple factors behind exactly why the number of drug-related deaths in B.C. dropped by 21 per cent in 2025 compared to the previous year.

Though the number of overdose deaths have been dropping sharply across North America, those working in the field say there's no reason to celebrate given thousands continue to die, and efforts to stop deaths should be stepped up.

"It's not necessarily a decline in the crisis itself. The drug supply is still as toxic and unpredictable as ever, if not more so," said Samuel Tobias, a researcher at the B.C. Centre on Substance Use and PhD candidate at the University of British Columbia.

Tobias is the lead author on a paper, set to be published in April's issue of the International Journal of Drug Policy, which found that as fentanyl concentrations increased in B.C.'s health service delivery areas, so did the number of fatal overdoses nearby.

The researchers used data from drug-checking services around the province from October 2018 until June 2025, and analyzed nearly 48,000 samples over that timespan.

"It was pretty consistent, over all of the included areas, that there is an association between fentanyl concentrations and how many people are dying that month," Tobias told CBC News.

"We were able to estimate that with each three quarter of a percentage point increase in the average fentanyl concentration in Vancouver, the city experienced one more death that month," he added.

The research found that the samples at drug checking sites became less concentrated in fentanyl over the years, which was associated with a drop in toxic drug deaths.

Fentanyl, a potent opioid, has become the most common drug in B.C.'s illicit supply ever since a public health emergency was declared in 2016.

Tobias notes, however, that lowered fentanyl concentration alone isn't the sole factor behind the provincewide, and continent-wide, drop in toxic drug deaths.

"Over time, it's become more and more complicated with other things like benzodiazepines and other tranquilizers. So, we don't know if this relationship will hold as the drugs become more complicated mixtures," he said.

In analyzing the reasons behind the potential drop in overdose deaths across Canada in 2024, the Public Health Agency of Canada says that it's likely that there is simply a smaller population now at risk.

"Population declines are in part because many lives were lost over previous years," the agency notes in a report from last December.