Evidence map›Paper›PMID 41656255›Full record

ArticleHarm reduction journal2026

Assessing the real-world performance of xylazine test strips for community-based drug checking in Los Angeles.

Caitlin A Molina, Joseph R Friedman, Adam J Koncsol, Ruby Romero, Morgan E Godvin, Leslie Nuñez, Karmen G Pang, Talya Tasini, Ezinne Okonkwo, Matthew Vu and 2 more

Abstract read
In one paragraph

Article in Harm reduction journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

12 authors.

Caitlin A MolinaDepartment of General Internal Medicine and Health Services Research, University of California, Los Angeles, Los Angeles, USA.
Joseph R FriedmanDepartment of Psychiatry, University of California, San Diego, San Diego, USA.
Adam J KoncsolDepartment of General Internal Medicine and Health Services Research, University of California, Los Angeles, Los Angeles, USA.
Ruby RomeroDepartment of General Internal Medicine and Health Services Research, University of California, Los Angeles, Los Angeles, USA.
Morgan E GodvinDepartment of General Internal Medicine and Health Services Research, University of California, Los Angeles, Los Angeles, USA.
Leslie NuñezUniversity of California, Los Angeles, Los Angeles, USA.
Karmen G PangUniversity of California, Los Angeles, Los Angeles, USA.
Talya TasiniUniversity of California, Los Angeles, Los Angeles, USA.
Ezinne OkonkwoUniversity of California, Los Angeles, Los Angeles, USA.
Matthew VuUniversity of California, Los Angeles, Los Angeles, USA.
Joshua SmithUniversity of California, Los Angeles, Los Angeles, USA.
Chelsea L ShoverDepartment of General Internal Medicine and Health Services Research, University of California, Los Angeles, Los Angeles, USA. CLShover@mednet.ucla.edu.

Funding

NRSA Training CoreTL1TR001883 · NCATS · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI ALEX BUI, Nina Thawata Harawa · 2016 to 2026
$8.6M
Ethno-epidemiology of HCV, HIV and Overdose associated with Drug Marketsand Drug TourismR01DA049644 · NIDA · UNIVERSITY OF CALIFORNIA, SAN DIEGO · PI STRATHDEE, STEFFANIE A. · 2020 to 2024
$8.2M
A binational cohort of the intersection between substance use, HIV, and associated comorbidities among people who inject drugs in San Diego, CA U01DA063078 · NIDA · UNIVERSITY OF CALIFORNIA, SAN DIEGO · PI Britt Skaathun, Steffanie A Strathdee · 2025 to 2026
$4.9M
Predicting fatal and non-fatal overdose in Los Angeles County with Rapid Overdose Surveillance Dashboard to target street-based addiction treatment and harm reduction servicesR01DA057630 · NIDA · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI David Goodman, Chelsea Leigh Shover · 2022 to 2026
$2.9M
Psychiatry Research Residency Training TrackR25MH101072 · NIMH · UNIVERSITY OF CALIFORNIA, SAN DIEGO · PI NEAL R SWERDLOW · 2013 to 2026
$2.8M
Adoption and scale-up of long-acting medications for opioid use disorder by U.S. clinicians.K01DA050771 · NIDA · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI SHOVER, CHELSEA LEIGH · 2021 to 2025
$893k
CDC HHS CDC-RFA-CE-23-0003NCATS NIH HHS TL1 TR001883NIDA NIH HHS K01 DA050771NIDA NIH HHS R01 DA049644NIDA NIH HHS R01 DA057630NIDA NIH HHS U01 DA063078NIMH NIH HHS R25 MH101072
6 · The paper itself

Abstract

backgroundThe veterinary sedative xylazine is increasingly found in illicit fentanyl and has been associated with numerous health harms. Xylazine test strips (XTS) are an emerging technology that can theoretically assist consumers in avoiding xylazine, but they require real-world validation. We leverage community-based drug checking program data to compare real-world XTS performance to 'gold standard' methods.

methodsSamples were initially assessed by dissolving 1 mg of drug product in 1 mL water and dipping an XTS ("first generation" Wisebatch™) in the sample. Subsequently, confirmatory testing was performed by sending samples to the National Institute of Standards and Technology for qualitative analysis using direct analysis in real-time mass spectrometry (DART-MS). A subset was analyzed quantitatively with liquid chromatography gas spectrometry (LC-MS) to quantify xylazine, fentanyl, and other compounds.

resultsA total of n = 1570 drug samples were analyzed between June 2023 and May 2025, and a total of n = 801 XTS were used. N = 715 comparisons between xylazine test strips and mass spectrometry results could be made, including n = 333 among samples that tested positive for fentanyl. Of these, n = 63 samples were confirmed to contain xylazine by mass spectrometry, of which the majority contained low concentrations (average concentration 2.3%; 78% of samples contained less than < 1% xylazine by weight). Of the 63, n = 34 were correctly identified as positive by XTS, yielding sensitivity of 54.0 %. Of n =  270 xylazine negative samples, n = 235 were correctly categorized (specificity = 87.0%). Most false positives occurred with lidocaine present.

conclusionsIn our sample, with a large percentage of low concentration xylazine samples, "first generation" Wisebatch XTS had a relatively low sensitivity, but higher specificity. This highlights the value of confirmatory testing and the complicated and often confusing nature of point-of-care test strips for novel substance detection. Lot testing and validation studies are needed to improve quality control in this area.

Indexed as

Hypnotics and SedativesIllicit DrugsSubstance Abuse DetectionXylazineFentanylHumansLiquid Chromatography-Mass SpectrometryLos AngelesFentanylHypnotics and SedativesIllicit DrugsXylazineConcordanceValidationXylazine test strips

Identifiers

PMID41656255
PMCPMC12977899

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.