A given drug sample can have multiple positive results for different drugs. One way to examine these results is to look at how often things are detected together. In the heatmaps below, we present the percentage of samples testing positive for the pair of drugs or drug categories listed. This comparison of the co-presence of two drugs cannot account for the fact that there are often three or more drugs present. The diagonal (where the column name and row name are the same) represents those samples testing positive for only that drug category (these samples may have tested positive for a drug category not listed here). The rows and columns are ordered from largest to smallest share of drug checking samples, alone or in combination. For more details on drug categories named, click here.
“Fentanyl” is a particularly complicated drug category as it almost always has other related compounds present due to manufacturing processes. For example, if you mouse over the row marked Fentanyl analogues and the column marked Fentanyl, you can see that 29% of these samples involved fentanyl and at least one fentanyl analogue, with or without any other drug mentioned here or any drug not included in the matrix.
If you mouse over the Fentanyl alone cell (Fentanyl row and Fentanyl column), you can see that exactly one sample tested positive for fentanyl itself and for no other drug category in the matrix. How can this be? Because 253 of 257 fentanyl-positive samples also had some other analgesic, shown in the Fentanyl and Other analgesics cell, in addition to the 91 positive for a fentanyl analogue and fentanyl itself. We should note that, as of the summer of 2024, other analgesics are now more common in "fentanyl pills" than fentanyls. If you move along the Fentanyl row (or column) you can see the share of all samples that tested positive for fentanyl itself and that other drug type, including 32% positive for a novel synthetic opioid other than the fentanyls. If you move along the Xylazine row or column, you can see that the 6 cases positive for xylazine also had fentanyl and other analgesics, and 2 of these also were positive for one or more fentanyl analogues. Four samples were not positive for any drug category in the matrix and so are not represented in any cell.
Drug testing sites can do little about potential cross-contamination: The container a client used may or may not have been used before. Therefore, any unusual combination may be due to cross-contamination and not represent drugs actually sold together. Results are cumulative and reflect all confirmatory testing results as of 11AM PST 19 November 2024.
What's in things sold as...
Using our interactive charts