86 samples checked: May 17 – 30, 2025

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Between May 17 and 30, 2025, 86 samples1 were collected from people who use drugs by the collection site members of Toronto’s Drug Checking Service, the flagship program of Ontario’s Drug Checking Community. Samples were analyzed by analysis site members of the program using gold standard technologies that are validated for overdose prevention drug checking. Of these 86 samples1, 38 were expected2 to be fentanyl (76% were drug samples3 and 24% were used drug equipment).

Key findings4

  • 5% of the expected2 fentanyl samples1 were known to be associated with an overdose – these samples contained a high-potency opioid5 (an opioid considered to be roughly as strong as or stronger than fentanyl) and a veterinary tranquilizer
  • 39% of the expected2 fentanyl samples1 contained multiple high-potency opioids5, including fentanyl, fluorofentanyl, a methylfentanyl-related drug, carfentanil, and/or protodesnitazene
  • 76% of the expected2 fentanyl samples1 contained a veterinary tranquilizer – 63% contained medetomidine and 26% contained xylazine
  • 58% of the expected2 fentanyl samples1 contained fluorofentanyl (at this time, we believe para-fluorofentanyl is circulating, which is considered to be roughly as strong as fentanyl)
  • 24% of the expected2 fentanyl samples1 contained a methylfentanyl-related drug (at this time, we believe ortho-methylfentanyl is circulating, which is considered to be roughly as strong as fentanyl)
  • 13% of the expected2 fentanyl samples1 contained a benzodiazepine-related drug, namely, ethylbromazolam and/or bromazolam
  • 8% of the expected2 fentanyl samples1 contained carfentanil (considered to be up to 100 times stronger than fentanyl) – we are observing a resurgence of carfentanil in Toronto’s unregulated fentanyl, heroin, and down supplies
  • 8% of the expected2 fentanyl samples1 contained a nitazene opioid, namely, protodesnitazene (considered to be as strong as fentanyl) or a “new” nitazene opioid metonitazepyne (considered to be 2 times stronger than fentanyl)
  • 39% of the expected2 fentanyl samples1 did not contain fentanyl – many of these samples instead contained fluorofentanyl, a methylfentanyl-related drug, and/or carfentanil
  • Amount of drugs found in expected2 fentanyl drug samples3:
    • In 15 expected2 fentanyl drug samples3:
      • 1.5% was the average amount6 of fentanyl found            
      • 0.9 – 2.7% was the range7 of fentanyl found in half of the drug samples3
    • In 16 expected2 fentanyl drug samples3:
      • 2.3% was the average amount6 of fluorofentanyl found                
      • 0.4 – 7.8% was the range7 of fluorofentanyl found in half of the drug samples3
    • In 6 expected2 fentanyl drug samples3:
      • 0.4% was the average amount6 of methylfentanyl-related drugs found
      • 0.2 – 1.9% was the range7 of methylfentanyl-related drugs found in half of the drug samples3
    • In 15 expected2 fentanyl drug samples3:
        • 0.4% was the average amount6 of medetomidine found
        • 0.2 – 1.9% was the range7 of medetomidine found in half of the drug samples3
    • In 15 expected2 fentanyl drug samples3:
      • 0.4% was the average amount6 of xylazine found
      • 0.2 – 1.1% was the range7 of xylazine found in half of the drug samples3

Expected fentanyl drug samples

  • 55% (16) of the expected2 fentanyl drug samples3 contained fentanyl and other drugs, including:
    • 94% (15) contained caffeine
    • 94% (15) contained a veterinary tranquilizer:
      • 75% (12) contained medetomidine (!)
      • 38% (6) contained xylazine (!)
    • 56% (9) contained at least one additional high-potency opioid5:
      • 44% (7) contained fluorofentanyl (!)
      • 31% (5) contained a methylfentanyl-related drug (!)
      • 13% (2) contained carfentanil (!)
      • 6% (1) contained metonitazepyne (!)
    • 19% (3) contained at least one benzodiazepine-related drug:
      • 13% (2) contained ethylbromazolam (!)
      • 6% (1) contained bromazolam (!)
    • 6% (1) contained acetyl fentanyl (!)

Unexpected noteworthy drugs found in other expected drug samples

Notes

1 | Samples: Includes both drugs and used drug equipment. Drugs could be a small amount of powder, crystals, rocks, blotter, or liquid, or a crushed bit of a pill. Used equipment could be a used cooker or filter, or leftover liquid from a syringe. For more information, view our terms of service.

2 | Expected (drug): When a sample is submitted to be checked, the drug that sample was bought or got as is recorded. We call it the “expected drug”. Knowing the expected drug helps us tailor our harm reduction advice. It also helps us understand contamination to drugs rather than combinations of drugs (e.g., fentanyl was found in a heroin sample rather than fen­tanyl and heroin were found together).

3 | Drug samples: Could be a small amount of powder, crystals, rocks, blotter, or liquid, or a crushed bit of a pill.

4 | Our key findings for the specified time period are based on results from both drugs and used drug equipment. There are limitations associated with including results from used drug equipment samples in unregulated drug market monitoring for a specified time period. Drug equipment – like cookers – are often re-used. The mass spectrometry technologies we use are so sensitive that very trace amounts of substances may be found. This means that when equipment is re-used, substances from past use may be found and included in results for the sample that is being checked. This can compromise the accuracy of drug market monitoring for a specified time period. For example, the substance was found in the used equipment sample but, if the equipment was re-used, is that substance circulating in the supply now or when the equipment was previously used. This is less of an issue for drug samples, which is why we prefer to rely on results from drug samples for time period-specific unregulated drug market monitoring. However, it is not always possible for a service user to submit a drug sample. We do the best we can with the samples we have access to.

5 | High-potency opioids: We classify an opioid “high-potency” if it is considered to be roughly as strong as or stronger than fentanyl.

6 | Average amount: We arrange the amounts of a substance found as a proportion of the total fentanyl drug sample from smallest to largest, determine the median (i.e., the middle number), and use that number as the “average”. For more information, view our amount of drugs found graph.

7 | Range: Known as the interquartile range, represents the middle 50% of the amounts of a substance found as a proportion of the total fentanyl drug sample. For more information, view our amount of drugs found graph

8 | Reporting similar substances together: These substances have a very similar chemical structure, and it is not currently possible for Toronto’s Drug Checking Service to differentiate between them. For this reason, we report these substances together. For more information, view our drug dictionary.

9 | Drug samples that unexpectedly contain noteworthy drugs and not the expected drug: Our reports highlight unexpected noteworthy drugs found in all checked drug samples. When noteworthy drugs are found unexpectedly in a drug sample and the expected drug is not present, we flag it but are hesitant to consider it contamination of the expected drug. Instead, we assume there is an issue with the expected drug: the person who sold or provided the drugs accidentally mixed up their drugs, the service user accidentally mixed up their drugs, or the expected drug was recorded incorrectly during sample collection. These samples require special consideration.

10 | High-potency opioid contamination: Based on the information we have about this sample, we are reporting it as contaminated with a high-potency opioid. However, it is very unusual that our program finds high-potency opioids unexpectedly in samples expected to be stimulants, psychedelics, and depressants, and these samples always require special consideration. There is increasing consensus in the drug checking community that the unexpected presence of high-potency opioids in other drug types is the product of accidental cross contamination rather than intentional adulteration. Cross contamination may result from poorly cleaned scales, storing drugs together (e.g., storing LSD in a baggie that was originally used for storing cocaine), or using drug equipment with different batches of drugs.

(!) | Unexpected noteworthy drug: “Noteworthy drugs” are drugs that (i) are linked to overdose or other adverse effects, (ii) are highly potent or related to highly potent drugs, or (iii) may not be desired by some service users. Noteworthy drugs are flagged when they are unexpectedly found in checked samples.