Crystal clear: Purity of street-level methamphetamine samples and methamphetamine-adulteration of other drugs in Los Angeles, 2023–2025
11 affiliations
- 1Division of General Internal Medicine and Health Services Research, Geffen School of Medicine, University of California, Los Angeles, CA, United States.
- 2Dept. of Health Policy & Management, Fielding School of Public Health, University of California, Los Angeles, CA, United States.
- 3Dept. of Anthropology, College of Social Sciences, University of California, Los Angeles, CA, United States.
- 4Homeless Outreach Program's Integrated Care System, Los Angeles, CA, United States.
- 5Bienestar Human Services, Los Angeles, CA, United States.
- 6The Sidewalk Project, Los Angeles, CA, United States.
- 7Community Health Project LA, Los Angeles, CA, United States.
- 8Geffen School of Medicine, University of California, Los Angeles, CA, United States.
- 9University of California, Los Angeles, Los Angeles, CA, United States.
- 10San Luis Obispo County Department of Behavioral Health, San Luis Obispo, CA, United States.
- 11University of California, San Diego, San Diego, CA, United States.
Abstract
Introduction: The United States has seen a rise in methamphetamine use disorders and methamphetamine-involved deaths. However, there is limited information on methamphetamine at the street level. We leverage data from a community-based drug checking program in Los Angeles to investigate the makeup of the retail illicit methamphetamine market and the extent methamphetamine plays a role as an adulterant in other drugs. Methods: Participants accessing a community-based drug checking program provided samples of drug products and completed brief interviews in Los Angeles County, California, from 2023 to 2025. Samples underwent laboratory-based qualitative and quantitative mass spectrometry. We quantitated the presence and concentration of methamphetamine as well as all other identified substances among samples expected only to be methamphetamine and samples expected to be another substance (e.g., fentanyl, heroin) where methamphetamine was found as an adulterant/contaminant. Results: Of N = 2193 total samples, n = 652 (29.7%) were methamphetamine-positive on DART-MS. In samples expected to contain methamphetamine, the mean purity was 78.2% (SD 24.0%; range <1% to ≈100%). As an unexpected component, the mean methamphetamine purity was 17.8% (SD 32.3%) and was mostly found in samples expected to be fentanyl, heroin, other amphetamines. Conclusions: Participants in Los Angeles seeking methamphetamine appear to frequently obtain high-purity samples that are rarely adulterated with other substances, although we observed a wide variation in concentration between samples. In contrast, drugs purchased without the expectation of containing methamphetamine had high prevalence of methamphetamine adulteration/contamination. Future research should expand methamphetamine surveillance techniques and investigate how variability in illicit markets may impact health outcomes.
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BibTeX
@article{koncsol2026crystal,
title = {{Crystal clear: Purity of street-level methamphetamine samples and methamphetamine-adulteration of other drugs in Los Angeles, 2023–2025}},
author = {Adam J Koncsol and Caitlin A Molina and Ruby Romero and Megan Grabill and Morgan E Godvin and Jesse Carrizal and Manuel Contreras and Oscar Arellano and Naomi Villanueva and Elham Jalayer and Spider Davila and Soma Snakeoil and Joshua Smith and Charles J Santamaria and Leslie Nuñez and Ezinne Okonkwo and Siddarth Puri and Joseph R Friedman and Chelsea L Shover},
journal = {Drug and Alcohol Dependence Reports},
year = {2026},
month = oct,
doi = {10.1016/j.dadr.2026.100482},
url = {https://doi.org/10.1016/j.dadr.2026.100482},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Crystal clear: Purity of street-level methamphetamine samples and methamphetamine-adulteration of other drugs in Los Angeles, 2023–2025
AU - Adam J Koncsol
AU - Caitlin A Molina
AU - Ruby Romero
AU - Megan Grabill
AU - Morgan E Godvin
AU - Jesse Carrizal
AU - Manuel Contreras
AU - Oscar Arellano
AU - Naomi Villanueva
AU - Elham Jalayer
AU - Spider Davila
AU - Soma Snakeoil
AU - Joshua Smith
AU - Charles J Santamaria
AU - Leslie Nuñez
AU - Ezinne Okonkwo
AU - Siddarth Puri
AU - Joseph R Friedman
AU - Chelsea L Shover
PY - 2026
DA - 2026/10/07
JO - Drug and Alcohol Dependence Reports
DO - 10.1016/j.dadr.2026.100482
UR - https://doi.org/10.1016/j.dadr.2026.100482
AB - Introduction: The United States has seen a rise in methamphetamine use disorders and methamphetamine-involved deaths. However, there is limited information on methamphetamine at the street level. We leverage data from a community-based drug checking program in Los Angeles to investigate the makeup of the retail illicit methamphetamine market and the extent methamphetamine plays a role as an adulterant in other drugs. Methods: Participants accessing a community-based drug checking program provided samples of drug products and completed brief interviews in Los Angeles County, California, from 2023 to 2025. Samples underwent laboratory-based qualitative and quantitative mass spectrometry. We quantitated the presence and concentration of methamphetamine as well as all other identified substances among samples expected only to be methamphetamine and samples expected to be another substance (e.g., fentanyl, heroin) where methamphetamine was found as an adulterant/contaminant. Results: Of N = 2193 total samples, n = 652 (29.7%) were methamphetamine-positive on DART-MS. In samples expected to contain methamphetamine, the mean purity was 78.2% (SD 24.0%; range <1% to ≈100%). As an unexpected component, the mean methamphetamine purity was 17.8% (SD 32.3%) and was mostly found in samples expected to be fentanyl, heroin, other amphetamines. Conclusions: Participants in Los Angeles seeking methamphetamine appear to frequently obtain high-purity samples that are rarely adulterated with other substances, although we observed a wide variation in concentration between samples. In contrast, drugs purchased without the expectation of containing methamphetamine had high prevalence of methamphetamine adulteration/contamination. Future research should expand methamphetamine surveillance techniques and investigate how variability in illicit markets may impact health outcomes.
SN - 2772-7246
ER -