More than 49,000 people have died of opioid overdose in Canada since 2016, with mortality rates escalating year-on-year and reaching 21 per 100,000 population in 2023. The Canadian Drugs and Substances Strategy locates the origins of this trend in the over-prescribing of opioids in the late 2000s, followed by increased diversion of opioids to the illicit market, then a rapid market shift to highly potent synthetic opioids. The present-day drug supply is dominated by fentanyl and characterised in research, advocacy and drug policy as ‘toxic ’ due to the presence of various potent contaminants including xylazine, nitazenes and non-medical benzodiazepines. Despite considerable government investment in responding to this situation, and occasional brief declines in overdose deaths in some regions, there are no signs of significant and sustained reductions in overdose mortality. This situation has been constituted as a ‘crisis’. Following Janet Roitman’s work critically interrogating the stakes of crisis and what the concept of crisis enables, we ask what is being constituted as the crisis in our field at this time, and the multiple effects of this claim. We seek to understand how a focus on the toxic drug supply as central to, or being, the crisis, shapes particular narratives regarding the boundaries and causes of this problem – and therefore also the possible solutions. Drawing on recent epidemiological analyses of persistent growth in overdose deaths pre-dating the conventionally accepted beginning of the overdose crisis in Canada, and reanalysing these findings through critical sociological inquir y, we argue that the dominant framing of the overdose crisis as a relatively recent matter of drug supply and contamination minimises the contribution of broader social and economic drivers of the long-term overdose trend. In doing so, it delineates certain targets for intervention (e.g. access to regulated alternatives to the illicit drug supply), but de-emphasises others (e.g. poverty reduction measures, housing, and social support). Informed by the concepts of slow death and slow crisis, as well as discussions of the social and economic dimensions of the overdose crisis in the United States and Canada, we argue that a reconfiguration of the overdose crisis in Canada may open up new possibilities for attending to the origins and boundaries of this situation, and therefore allow for different, and more equitable and just, responses that seek to address long-standing ecological processes catalysing growth in overdose mortality.