Drug Checking Findings: October - December 2025

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The Philadelphia Department of Public Health (PDPH) Division of Substance Use Prevention & Harm Reduction (SUPHR) received results for 532 drug samples collected between October and December 2025 and submitted for laboratory analysis. Most samples were drug litter found in public spaces by PDPH SUPHR staff.

Samples were tested by the Center for Forensic Science Research and Education (CFSRE) using advanced toxicology methods. Findings highlight a rapidly changing drug supply that can complicate overdose recognition, response, and withdrawal management.

Overview

Sample Collection

PDPH SUPHR staff collected primarily drug litter samples, including glassine bags, centrifuge tubes, and other paraphernalia, found in public spaces between October and December 2025 (Table 1). While these samples provide valuable insight into drug use patterns, their origin and handling introduce uncertainty. It is often unclear whether the detected substances were sold together, mixed by the person who consumed the drug, or contaminated after disposal. Samples were also submitted by a collaborating community-based organization and collected through an amnesty box located in Kensington. These results are based on a limited sample and should not be considered representative of the broader Philadelphia drug supply but can be used for harm reduction, early warning, and informational purposes.

Most samples were collected in the Kensington area (Table 2). Center City accounted for 24 percent of samples, while smaller numbers came from the North/Northeast (7 percent), West (3 percent), and South/Southwest (3 percent). Five sample locations were unknown.

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Table 1. Drug Sample Collection Volume, October - December 2025

Month n (%)
October 265 (50)
November 130 (24)
December 137 (26)

Laboratory Analysis

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Table 2. Drug Sample Collection Volume by City Section, October-December 2025

Section n (%)
Kensington 331 (62)
Center City 128 (24)
Northeast/North 37 (7)
South/Southwest 15 (3)
West 16 (3)
Unknown 5 (1)

The CFSRE laboratory utilizes innovative analytical techniques for drug testing, employing comprehensive non-targeted data acquisition through gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF). The testing panel includes more than 1,100 substances, including a wide range of novel psychoactive substances (NPS) and other relevant compounds. This report includes results from both GC-MS and LC-QTOF analysis.

The quarterly analysis period is defined by the date on which SUPHR staff collected the samples. Initial classification of drug litter samples is decided by the staff submitting the sample based on visual characteristics of the drug product, packaging type, and/or associated paraphernalia at the time of collection. Following laboratory analysis, samples are reclassified according to the primary substance identified.

Samples with Primary Substance Heroin or Fentanyl (n=349) 

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Table 3.Most Frequent Co-Occurring Substances in Samples with Fentanyl or Heroin as the Primary Drug and Percentage Change Since 2025 Q3

Substance n(%) Percent Change
Fentanyl 340 (97) + 1%
4-ANPP 335 (96) + 8%
Medetomidine 317 (91) + 6%
Phenethyl-4-ANPP 304 (87) + 19%
Lidocaine 287 (82) + 12%
Procaine 283 (81) + 20%
Tetracaine 225 (64) + 7%
Cocaine 215 (61) - 4%
Xylazine 179 (51) + 35%
Acetylfentanyl 142 (41) + 37%
Caffeine 132 (38) + 18%
Acetaminophen 121 (35) - 1%
Carfentanil 85 (24) + 15%
Methamphetamine 70 (20 + 16%
Heroin 46 (13) - 26%
An average of 11.4 substances were identified in samples with fentanyl (n=318) or heroin (n=31) as the primary substance (range: 3-28). One suspected fentanyl sample was excluded because no active substances were detected. Three samples initially suspected by SUPHR staff to be cocaine (n=1), methamphetamine (n=1), and K2 (n=1) were reclassified as fentanyl following laboratory analysis.

Figure 1. Sedatives in Samples with Fentanyl or Heroin as the Primary Substance

Fentanyl remained the most frequently detected substance in suspected dope samples, present in 96 percent of samples, with no change in percentage since 2025 Q1–Q2 (UPDATE) (Table 1) 1. Carfentanil was identified in 21 percent of samples with fentanyl as the primary substance, in comparison to being detected in only one sample during the first half of the year that had a primary substance of cocaine (fentanyl was also present in that sample in a lesser amount). Its presence is a significant concern, given that its extreme potency means even slight variations in concentration can significantly increase the risk of death among people who use drugs.2
Fentanyl remained the most frequently detected substance in suspected dope samples, present in 97 percent of samples, with one percent increase since 2025 Q3 (Table 3)1. Carfentanil was present in 24 percent of samples that had fentanyl as a primary substance, a 15 percent increase since the last quarter. It was also detected in one sample that had a primary substance of cocaine (the sample was packaged as dope in a blue glassine bag and fentanyl was also present in a lesser amount). Its presence is a significant concern, given that its extreme potency means even slight variations in concentration can significantly increase the risk of death among people who use drugs.2 Acetylfentanyl, a fentanyl analog approximately 30 percent less potent than fentanyl,3 was detected in 41 percent of samples, marking a 37 percent increase since the prior quarter. Heroin was detected in 13 percent of samples, a 26 percent decrease from Q3 2025.) Opioid precursors 4-ANPP (96 percent) and phenethyl-4-ANPP (87 percent) remained highly prevalent. Heroin was detected in 13 percent of samples, a 26 percent decrease from Q3 2025. Nine samples with a primary substance of heroin did not have fentanyl present (29 percent of dope samples with heroin as a primary substance).
Veterinary sedatives continue to appear in the illicit dope supply with 95 percent of all dope samples containing xylazine and/or medetomidine. The percentage of dope without sedatives present has decreased from 10 percent during 2025 Q3 to 5 percent. Medetomidine is increasingly being detected in most suspected dope samples (91 percent). Xylazine was detected in 51 percent of samples, a 35 percent increase from last quarter. Co-detection of xylazine and medetomidine increased from 34 percent during Q3 2025 to 48 percent during Q4 2025, representing a 42 percent increase (Figure 1). The presence of sedatives further complicates overdose reversal efforts using naloxone, which does not reverse the sedative effects of medetomidine and xylazine. Symptoms of medetomidine withdrawal include intractable vomiting, excessive diaphoresis, hypertensive emergency, waxing and waning hypoactive encephalopathy, tremors, and tachycardia. 4,5 In a retrospective case series across three hospital systems in Philadelphia of patients who presented for severe fentanyl withdrawal suspected to be complicated by medetomidine, 77 percent required admission to the intensive care unit, and 20 percent were intubated.6
Three samples collected in December 2025 contained trace amounts of azaperone, a butyrophenone antipsychotic used primarily in veterinary medicine as a sedative and antiemetic.7 Philadelphia non-profit Savage Sisters also reported detecting azaperone in at least one sample collected in December 2025 through their drug checking surveillance program with Friends Institute and the National Institute of Standards & Technology (NIST).8,9 At the time of this report, we have had an additional four samples test positive for azaperone in Q1 2026, but it remains to be found only in trace amounts. At clinically meaningful doses, azaperone’s effects are expected to resemble those of other first-generation antipsychotics, including sedation, QTc prolongation, and dystonic reactions, with neuroleptic malignant syndrome as a rare but life-threatening complication. Hypotension, respiratory depression, and seizures may occur at higher doses but can be difficult to distinguish from opioid or α2-agonist effects. Given that azaperone has thus far been detected only in trace amounts in a few samples, clinically significant effects are not anticipated; however, should concentrations increase, clinicians should be alert for an antipsychotic toxidrome and prolonged sedation following naloxone administration.10,11
Local anesthetics, including lidocaine (82 percent), procaine (81 percent), and tetracaine (64 percent), remained commonly detected, with each showing increased detection. At least one local anesthetic was present in 97 percent of dope samples (n=338). Fentanyl overdoses with local anesthetics on board have been reported to have atypical presentations that include numbness, bradycardia, hypotension, lightheadedness, confusion, acute anxiety, methemoglobinemia, respiratory depression, and seizures.12 Some of these symptoms are commonly known as Local Anesthetic Systemic Toxicity (LAST) is a rare, life-threatening complication from local anesthetics entering the bloodstream and affecting the central nervous system and cardiovascular system, causing symptoms like tinnitus, altered mental state, seizure, arrhythmias, hypotension, and cardiac arrest.13
Cocaine was detected in 61 percent of suspected dope samples. Notably, 60 percent of samples (n = 210) contained fentanyl, cocaine, and at least one sedative. Methamphetamine detection in samples with fentanyl as the primary substance also increased by 16 percent. The frequent detection of stimulants highlights continued polysubstance use, potentially reflecting attempts to counteract the sedative effects of the current drug supply.14 This combination, often referred to as “speedballs” (cocaine and fentanyl) or “goofballs” (methamphetamine and fentanyl), carries significant risks, including coma, stroke, respiratory failure, myocardial infarction, brain aneurysm, and death.15 The Philadelphia Department of Public Health issued a health advisory in October 2025, noting a 110 percent increase in drug–use–related emergency department visits where seizures were the chief or primary complaint.16 Elevated seizure risk has been associated with cocaine, methamphetamine, and local anesthetics.12

Samples with Primary Substance Cocaine (n=150) 

An average of 3.1 substances were identified in samples with cocaine as a primary substance (range: 1 to 17). Four suspected cocaine samples were excluded because no active substances were detected. Twenty-two samples initially suspected by SUPHR staff to be methamphetamine (n=13) and dope (n=9) were reclassified as cocaine following laboratory analysis.
Most cocaine samples contained relatively few adulterants, and several substances showed notable decreases compared to the previous reporting period (Table 4). The most common co-occurring substances were lidocaine (13 percent) and phenacetin (10 percent), both typical adulterants associated with cocaine. Phenacetin is a recognized carcinogen and exposure has been linked to like nephrotoxicity, nephropathy, hemolytic anemia, methemoglobinemia, as well as increased risks of kidney and bladder cancer.17 Medetomidine (7 percent) and fentanyl (4 percent) were present in a small number of samples with a primary substance of cocaine. Given that these samples were drug litter, these results should not be taken to imply that medetomidine or fentanyl are present in the broader cocaine supply. Nonetheless, these findings highlight continuing patterns of polysubstance use, whether deliberate or accidental.
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Table 4.Most Frequent Co-Occurring Substances in Samples with Cocaine as the Primary Drug and Percentage Change Since 2025 Q3

Substance n (%) Percent Change
Lidocaine 20 (13) - 57%
Phenacetin 15 (10) + 24%
Medetomidine 10 (7) - 34%
Caffeine 8 (5) - 58%
Fentanyl 6 (4) - 67%
Procaine 6 (4) - 46%

Samples with Primary Substance Methamphetamine (n=15) 

An average of 2.1 substances were detected in samples with methamphetamine as a primary substance (range: 1 to 8). Two suspected methamphetamine samples were excluded because no active substances were detected. A larger number of methamphetamine samples is needed to strengthen future analysis.

Decreases in fentanyl (31 percent), lidocaine (31 percent), and cocaine (23 percent) were observed in methamphetamine samples (Table 5). However, additional samples are needed to support a more detailed analysis. As with cocaine, these findings should not be taken to indicate that fentanyl or medetomidine are routinely found in methamphetamine. They do, however, underscore ongoing patterns of polysubstance use.

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Table 5. Most Frequent Co-Occurring Substances in Samples with Methamphetamine as the Primary Drug and Percentage Change Since 2025 Q31

Substance n (%) Percent Change
Cocaine 3 (20) - 23%
Dimethyl sulfone 3 (20) + 55%
Fentanyl 2 (13) - 31%
Lidocaine 2 (13) - 31%
Medetomidine 2 (13) - 17%

  • Nine samples with no active substances were excluded from all analyses.

  • Ten samples containing cannabis (n=6), ketamine (n=1), LSD (n=1), MDMA (n=1), and testosterone deanoate (n=1) were excluded from this report due to the limited sample size, which was insufficient for meaningful analysis.

  • Drug litter samples, while non-invasive and informative, limit conclusions about the illicit drug supply.

Additional Notes

This report was prepared by Tracy Esteves Camacho, MPH; Rose Laurano, MPH; Aoife Frankel, MPH; Joseph D’Orazio, MD; Daniel Teixeira da Silva, MD, MSHP.  This work is funded by the Centers for Disease Control and Prevention (CDC) through the Overdose Data to Action (OD2A) grant.

Acknowledgements

  1. Philadelphia Department of Public Health. Drug Checking Report: July-September 2025. 2025. Accessed January 15, 2026. https://www.substanceusephilly.com/q322025

  2. Philadelphia Department of Public Health. Health Update: Carfentanil Is Increasingly Detected in Drug Supply and Overdose Deaths. 2025. https://hip.phila.gov/document/5891/PDPH-HAN-Carfentanil-11.13.2025.pdf/

  3. Higashikawa Y, Suzuki S. Studies on 1-(2-phenethyl)-4-(N-propionylanilino)piperidine (fentanyl) and its related compounds. VI. Structure-analgesic activity relationship for fentanyl, methyl-substituted fentanyls and other analogues. Forensic Toxicol. 2008;26:1-5. doi:10.1007/s11419-007-0039-1

  4. Philadelphia Department of Public Health. Health Alert: Hospitals and Behavioral Health Providers Are Reporting Severe and Worsening Presentations of Withdrawal among People Who Use Drugs (PWUD) in Philadelphia. 2024.

  5. Philadelphia Department of Public Health. Health Update: Responding to Overdose and Withdrawal Involving Medetomidine. 2025. https://hip.phila.gov/document/5444/PDPH-HAN-SUPHR-Medetomidine-06.10.2025_1Zu1OZ4.pdf/

  6. London KS, Huo S, Murphy L, et al. Severe Fentanyl Withdrawal Associated With Medetomidine Adulteration: A Multicenter Study From Philadelphia, PA. J Addict Med. Published online August 1, 2025. doi:10.1097/ADM.0000000000001560

  7. National Center for Biotechnology Information. PubChem Compound Summary for CID 15443, Azaperone. Accessed January 28, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/Azaperone

  8. Savage Sisters. Savage Sisters on Instagram: “This is data from the Philly Dope Supply. We tested 198 samples in 2025. #testing #philly #substance #recovery #safety.” Instagram. December 19, 2025. Accessed January 14, 2026. https://www.instagram.com/savagesistersrecovery/p/DScqxntDrFv/

  9. National Institute of Standards and Technology. RaDAR Newsletter - December 2025. January 13, 2026. Accessed January 14, 2026. https://content.govdelivery.com/accounts/USNIST/bulletins/403d5ed

  10. James LP, James L, Abel K, Wilkinson J, Simpson PM, Nichols M. Phenothiazine, Butyrophenone, and Other Psychotropic Medication Poisonings in Children and Adolescents. J Toxicol Clin Toxicol. 2000;38(6). doi:10.1081/CLT-100102010

  11. Long N. Phenothiazines and butyrophenones. November 3, 2020. Accessed January 28, 2026. https://litfl.com/phenothiazines-and-butyrophenones/

  12. Palamar JJ, DeBord JS, Krotulski AJ, Goldberger BA. Local Anesthetics Adulterating the Illicit Fentanyl Supply. JAMA Psychiatry. Published online May 21, 2025. doi:10.1001/jamapsychiatry.2025.0952

  13. Song K, Blankenship RB, Derian A. Local Anesthetic Toxicity. In: StatPearls. StatPearls Publishing; 2025. Accessed January 28, 2026. http://www.ncbi.nlm.nih.gov/books/NBK499964/

  14. Ivsins A, Fleming T, Barker A, et al. The practice and embodiment of “goofballs”: A qualitative study exploring the co-injection of methamphetamines and opioids. Int J Drug Policy. 2022;107:103791. doi:10.1016/j.drugpo.2022.103791

  15. Lee-Easton M, Magura S, Abu-Obaid R, et al. Polysubstance use patterns among individuals applying for opioid-use disorder treatment in the U.S. J Subst Use. 2024;0(0):1-8. doi:10.1080/14659891.2024.2372093

  16. Philadelphia Department of Public Health. Health Advisory: Increasing Incidence of Seizures among People Who Use Drugs (PWUD) in Philadelphia. 2025. https://hip.phila.gov/document/5756/PDPH-HAN_SUPHR_Seizures-10.7.2025.pdf

  17. Mohr A, Brown T, Nelson L, Logan B. Phenacetin: A Toxic Adulterant Found in Illicit Street Drugs. Fredric Rieders Family Foundation; 2021. https://www.cfsre.org/images/content/reports/public_alerts/2021.04.20.Public-Alert_Phenacetin_Final.pdf

References