Drug Checking Findings: July-September 2025

Authors: Tracy Esteves Camacho, MPH; Rose Laurano MPH; Daniel Teixeira da Silva MD, MSHP

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The Philadelphia Department of Public Health (PDPH) Division of Substance Use Prevention & Harm Reduction (SUPHR) received results for 588 drug samples collected between July and September 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 July and September 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. Because these results are based on a limited sample, they should not be considered representative of the broader drug market in Philadelphia. 

Most samples were collected in the Kensington area (Table 2). Center City accounted for 10 percent of samples, while smaller numbers came from the North/Northeast (6 percent) and South/Southwest (6 percent). Seven sample locations were unknown. 

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Table 1. Drug Sample Collection Volume, July–September 2025

Month n(%)
July 186(31)
August 145 (25)
September 257 (44)

Laboratory Analysis

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Table 2. Drug Sample Collection Volume by City Section, July–September 2025

Section n(%)
Kensington 441(75)
Center City 62(10)
Northeast/North 34(6)
South/Southwest 34(6)
West 10(2)
Unknown 7(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. 

The initial classification of drug litter samples is based on the appearance of the drug product, the type of packaging, and/or the type of paraphernalia being submitted. Samples are later re-categorized according to the primary active substance identified through laboratory analysis. For example, twenty-one suspected dope samples were recategorized as cocaine (n=16), methamphetamine (n=4), and dimethocaine (n=1). Five suspected cocaine samples were recategorized to methamphetamine (n=3), fentanyl (n=1), and ketamine (n=1). Additionally, one methamphetamine sample was initially believed to be a prescription amphetamine pill, and another was suspected to be K2 (plant material). 

Samples with Primary Substance Heroin or Fentanyl (n=364) 

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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 Q1 & Q2

Substance n(%) Percent Change
Fentanyl 350 (96) No change
4-ANPP 325 (89) + 14%
Medetomidine 312 (86) + 7.5%
Lidocaine 267 (73) + 14%
Phenethyl-4-ANPP 266 (73) + 28%
Procaine 246 (68) + 74%
Cocaine 233 (64) + 167%
Tetracaine 220 (60) + 87%
Xylazine 138 (38) + 123%
Acetaminophen 128 (35) + 250%
Caffeine 117 (32) + 68%
Acetylfentanyl 108 (30) + 131%
Carfentanil 77 (21) NAa
Heroin 65 (18) + 38%
An average of 9.6 substances were identified in samples with fentanyl or heroin as a primary substance (range: 2 to 26). Twelve suspected dope submissions were excluded because no active substances were found. One sample with a primary substance of fentanyl was initially suspected to be cocaine.
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
Local anesthetics, including lidocaine (73 percent) and tetracaine (60 percent), continued to be commonly detected, with tetracaine showing a substantial increase of 87 percent. Procaine also increased markedly by 74 percent, indicating a growing prevalence of cutting agents potentially used to mimic the numbing effects of opioids. 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.3
Veterinary sedatives continue to appear in the illicit opioid supply, with medetomidine being detected in most suspected dope samples (86 percent). Xylazine was present in 38 percent of samples, a 124 percent increase in detection since the first half of the year. Co-detection of xylazine and medetomidine increased from 13 percent during Q1 and Q2 of 2025 to 34 percent during Q3 of 2025, representing a 162 percent increase (Figure 1). The percentage of samples with fentanyl or heroin as the primary substance without sedatives present (xylazine or medetomidine) has decreased from 16 percent to 10 percent. The presence of sedatives further complicates overdose reversal efforts using naloxone, which does not reverse sedative effects. 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 Acetylfentanyl, an analog of fentanyl that is 30 percent less potent than fentanyl7, was present in 30 percent of samples. Opioid precursors 4-ANPP (89 percent) and phenethyl-4-ANPP (73 percent) remained common. Heroin was detected in 18 percent of samples.

Samples with Primary Substance Cocaine (n=149) 

An average of 3.2 substances were identified in samples with cocaine as a primary substance (range: 1 to 12). Four suspected cocaine samples were excluded because no active substances were detected. Sixteen of the submissions with a primary substance of cocaine were initially suspected to be dope. 

While most cocaine samples contained relatively few adulterants, several substances showed notable increases compared to the previous reporting period (Table 4). The most common co-occurring substances were lidocaine (31 percent) and caffeine (13 percent), both typical adulterants associated with cocaine. Fentanyl (+71 percent) and medetomidine (+43 percent) demonstrated substantial increases. Given that these samples were drug litter, these results should not be taken to imply that fentanyl or medetomidine are present in the broader cocaine supply. Nonetheless, these findings highlight continuing patterns of polysubstance use, whether deliberate or accidental. 

Cocaine was found in 64 percent of suspected dope samples, a 167 percent increase since the last report. Additionally, most of the cocaine-positive samples also had medetomidine and/or xylazine present (62 percent). The detection of stimulants in suspected dope samples illustrates the ongoing trend of polysubstance use, potentially as people who use dope attempt to counteract the sedative effects of the drug supply. Commonly referred to as “speed balling”, this practice carries serious health risks, including coma, stroke, respiratory failure, heart attack, brain aneurysm, and death.8 PDPH issued a health advisory highlighting a 110% increase in drug use-related emergency department visits where seizures were the chief or primary complaint.9 The elevated seizure risk has been linked to cocaine, methamphetamine, and local anesthetics.
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Table 4. Most Frequent Co-Occurring Substances in Samples with Cocaine as the Primary Drug and Percentage Change Since 2025 Q1 & Q2

Substance n(%). Percent Change
Cocaine 149(100) No change
Lidocaine 46(31) +15%
Caffeine 19(13) +117%
Fentanyl 18(12) +71%
Medetomidine 15(10) +43%
Phenacetin 12(8) No change
Procaine 11(7) + 250%

Samples with Primary Substance Methamphetamine (n=31) 

An average of 3.1 substances were detected in samples with methamphetamine as a primary substance (range: 1 to 14). No suspected methamphetamine samples were excluded, but a larger number of methamphetamine samples is needed to strengthen future analysis. Four samples with a primary substance of methamphetamine were initially suspected to be dope (fentanyl and/or heroin), three were suspected to be cocaine, one was suspected to be a prescription amphetamine pill, and one was suspected to be K2 and consisted of plant material residue.  

Increases in cocaine (26 percent), lidocaine (19 percent), and fentanyl (19 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 Q1 & Q2

Substance n(%). Percent Change
Methamphetamine 31(100) No change
Cocaine 8(26) +225%
Caffeine 19(13) +117%
Fentanyl 6(19) +27%
Lidocaine 6(19) +137%
Medetomidine 5(16) + 7%

  • Twenty-three samples with no active substances were excluded from all analyses. 

  • Twenty-one samples containing cannabis (n=9), K2 (n=5), and other (n=7) 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

  1. Philadelphia Department of Public Health. Drug Checking Report: Jan-July 2025.; 2025. Accessed October 27, 2025. https://www.substanceusephilly.com/q1q22025 

  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. 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 

  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. 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 

  8. 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 

  9. 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 

References