Sample Volume
Drug Type Breakdown
Adulterant Co-occurrence
Fentanyl Purity Over Time
Individual Data Points
Alpha-2 Agonist Transition
Xylazine Avg Purity in Co-occurrences
Medetomidine Avg Purity
Local Anesthetic Adulterants
Cocaine Purity
Methamphetamine Purity
Ketamine Purity
para-Fluorofentanyl
Substance Summary Table
| Substance | Category | Cases | Overall Avg Purity | Purity Range | Trend |
|---|---|---|---|---|---|
| Fentanyl | Opioid | 347 | 6.9% | 0.1–59%* | ↓ Declining |
| Cocaine | Stimulant | 100 | 59.4% | 5–90% | ↑ Rising in 2025 |
| Methamphetamine | Stimulant | 87 | 57.7% | 15–85% | → Stable/slight decline |
| Ketamine | Dissociative | 54 | 57.9% | 20–70% | New in 2025 |
| Xylazine | Adulterant | 144 | 25.1% | 0.2–80% | ↓ Fading post-2024 |
| Medetomidine | Adulterant | 107 | 12.2% | 0.3–30% | ↑ Dominant 2025+ |
| Lidocaine | Local Anesthetic | 180 | 17.9% | 0.1–55% | → Persistent |
| para-Fluorofentanyl | Opioid Analog | 51 | 1.3% | 0.1–8% | ↓ Near zero post-2024 |
| MDMA | Entactogen | 19 | 42.6% | 1–65% | Emerging 2025 |
Fentanyl Purity Is Declining
Average fentanyl purity dropped approximately 41% from early 2024 (~9%) to 2025–2026 (~5.3%). This likely reflects increasing dilution as distributors mix fentanyl with a growing array of adulterants — particularly the new alpha-2 agonist medetomidine — rather than any reduction in supply. Lower purity in a single bag does not mean lower overdose risk: inconsistent mixing creates dangerous hotspots.
Medetomidine Has Replaced Xylazine
The data show a near-complete transition from xylazine to medetomidine as the primary alpha-2 agonist adulterant in the fentanyl supply. This shift occurred rapidly in early 2025 — by April 2025, medetomidine appeared in the majority of fentanyl samples while xylazine had become rare. This has significant implications for harm reduction messaging, naloxone distribution, and wound care guidance.
para-Fluorofentanyl Spike and Retreat
para-Fluorofentanyl appeared in 51 samples, with a dramatic spike in September 2024 (20 co-detections) before essentially vanishing from the supply. This pattern — emergence, peak, disappearance — is consistent with a brief supply chain incursion. pFF is roughly equipotent to fentanyl and poses similar overdose risk.
Cocaine Purity Is High and Rising
After a notable dip to 23–28% average in Sep–Oct 2024, cocaine purity recovered sharply. In 2025, average monthly purity frequently exceeded 65–75%, with some samples testing above 90%. This is consistent with relatively uncut product, though high purity cocaine still carries significant cardiovascular risk and fentanyl contamination cannot be ruled out on all samples.
Ketamine and MDMA Are Now Routine
Ketamine emerged as a significant sample category in April 2025, with 54 total cases detected through February 2026. MDMA first appeared in June 2025. These substances were largely absent from earlier data, suggesting PA Groundhogs is now serving a broader harm reduction population — including party drug users — and that messaging should extend beyond the opioid-only frame.
Program Volume Is Growing
Monthly sample throughput has generally increased over the dataset period, with strong collection months in Sep 2024 (63), Jun 2025 (60), Oct 2025 (45), and Jan 2026 (40). Collection volume is driven by outreach events and partnerships rather than continuous intake, which produces the uneven monthly pattern. The overall trajectory reflects program growth.
