The opioid crisis continues to evolve across North America, with illicit fentanyl playing a central role in overdose deaths and addiction-related harms. While healthcare professionals have long recognized fentanyl as an exceptionally powerful opioid, relatively little information has been available about the actual amounts consumed by people who regularly use illicit fentanyl.
A recent study conducted in Los Angeles offers important new insights. Researchers analyzed fentanyl samples obtained through community drug-checking programs and combined those findings with self-reported consumption patterns from people who regularly use fentanyl. Their results suggest that average daily opioid exposure among participants may be dramatically higher than previously understood.
The findings could have major implications for addiction treatment, overdose prevention, and public health policy.
Fentanyl is a synthetic opioid that is significantly more potent than many prescription pain medications and traditional street opioids such as heroin. Pharmaceutical fentanyl is used medically for severe pain management, but illicitly manufactured fentanyl has increasingly dominated illegal opioid markets in recent years.
Because illicit fentanyl is often produced without quality control standards, the strength and composition of products can vary substantially. This variability increases overdose risk because users may not know the exact potency of the substance they are consuming.
The transition from heroin-dominated markets to fentanyl-dominated markets has been associated with a sharp rise in overdose deaths throughout the United States and Canada.
The research team analyzed more than 500 fentanyl samples collected through a community-based drug-checking initiative in Los Angeles County between 2023 and 2026.
Using laboratory testing methods, researchers measured the concentration of fentanyl in each sample. They then combined those results with survey responses from individuals who reported regular fentanyl use.
Participants provided information about:
Researchers used statistical modeling to estimate the morphine milligram equivalent (MME) exposure associated with reported fentanyl consumption.
MME is a commonly used measurement that allows healthcare professionals to compare the potency of different opioids using a standardized scale.
One of the most significant findings was the large variation in fentanyl purity.
Researchers found that the average fentanyl concentration in tested samples was approximately 12.5%. However, some samples contained much lower concentrations while others contained substantially higher levels.
Participants reported consuming an average of approximately one gram of fentanyl product per day.
After accounting for purity levels, bioavailability, and opioid potency conversions, researchers estimated that average daily exposure was roughly 8,888 morphine milligram equivalents.
Even under the most conservative modeling scenarios, estimated opioid exposure remained extremely high.
This level of opioid exposure is several orders of magnitude above commonly referenced clinical opioid prescribing thresholds.
The results help explain several challenges that have emerged during the fentanyl era.
One of the biggest concerns is the unpredictable nature of illicit fentanyl products.
When potency varies significantly between batches, individuals may unintentionally consume far more opioid than expected. This unpredictability contributes to the high rate of overdose events observed in many communities.
Researchers noted that some products contained only small amounts of active fentanyl, while others were many times stronger. Such variability creates an environment where even experienced users face substantial risk.
Repeated exposure to high-potency opioids can lead to significant increases in tolerance.
As tolerance develops, individuals often require larger amounts of opioids to achieve the same effects or to avoid withdrawal symptoms.
The study suggests that many regular fentanyl users may develop opioid tolerance levels far beyond those typically encountered in clinical settings.
This may help explain why some people report difficulty transitioning away from fentanyl or returning to less potent opioids.
The findings also have important implications for medications used to treat opioid use disorder.
Common treatments such as methadone and buprenorphine remain among the most effective tools available for reducing opioid-related mortality and supporting recovery.
However, healthcare providers have increasingly reported difficulties initiating treatment for individuals who primarily use fentanyl.
Researchers suggest that extremely high levels of opioid tolerance may be one factor contributing to these challenges.
Understanding the scale of fentanyl exposure could help clinicians develop more effective treatment strategies and improve patient retention in care.
An important aspect of this study is the use of community-based drug-checking services.
These programs allow individuals to submit samples for laboratory analysis, providing valuable information about the contents of substances circulating within local drug markets.
Drug-checking initiatives can:
The information generated through these programs can help healthcare providers, researchers, and policymakers better understand evolving drug markets.
Although the findings are significant, the researchers emphasized several limitations.
The study focused on participants in Los Angeles, meaning results may not fully represent conditions in other regions.
Drug-checking participants may also differ from the broader population of people who use opioids. As a result, consumption patterns observed in the study may not apply universally.
Additionally, estimating opioid exposure requires assumptions regarding factors such as bioavailability and potency conversion ratios. While researchers used evidence-based methods, different assumptions could influence final estimates.
Nevertheless, across multiple sensitivity analyses, estimated exposure levels remained remarkably high.
The study highlights the extraordinary potency of the modern illicit fentanyl supply and underscores the complexity of addressing the ongoing opioid crisis.
For healthcare professionals, the findings may improve understanding of opioid tolerance and treatment needs among people who regularly use fentanyl.
For policymakers and public health organizations, the research reinforces the importance of overdose prevention initiatives, harm reduction programs, and expanded access to evidence-based treatment.
Most importantly, the study demonstrates how dramatically the opioid landscape has changed during the fentanyl era. Understanding these changes is essential for developing effective responses and reducing opioid-related harm.
This research provides one of the most detailed estimates to date of opioid exposure among people who regularly use illicit fentanyl. By combining laboratory testing with real-world consumption data, researchers found that average opioid exposure may be thousands of morphine milligram equivalents per day.
While additional research is needed to confirm how these findings apply across different regions and populations, the study offers valuable insight into the scale of fentanyl-related risk and the challenges facing treatment providers today.
As communities continue working to reduce overdose deaths and improve access to care, data-driven research such as this can play a critical role in shaping effective public health strategies.
Godvin M, Friedman JR, Molina CA, Koncsol AJ, Romero R, Juurlink DN, and Shover CL. Estimating the Daily Milligrams of Morphine Equivalent of Illicit Fentanyl Use in Los Angeles: Clinical and Epidemiological Implications. Drug and Alcohol Dependence (2026). DOI: 10.1016/j.drugalcdep.2026.113224.
This article is intended for educational and informational purposes only. It does not provide medical advice, diagnosis, or treatment recommendations. Individuals struggling with opioid use disorder or substance use concerns should seek guidance from qualified healthcare professionals or licensed addiction specialists. Research findings discussed in this article should not be interpreted as clinical recommendations for any individual patient.
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