Los Angeles drug checking data reveals staggering levels of daily fentanyl consumption

A recent study published in the journal Drug and Alcohol Dependence provides evidence that people who regularly use illicit fentanyl consume doses equivalent to nearly 9,000 milligrams of oral morphine every day. These findings suggest that standard medical treatments for opioid dependence might need significant adjustments to account for the extremely high tolerance levels seen in today’s illicit drug market. By quantifying exactly how much of the drug people are using, scientists hope to improve recovery outcomes.

Fentanyl is a synthetic opioid that has become the primary driver of the overdose crisis in North America over the past decade. Because it is inexpensive to produce and highly potent, it has largely replaced drugs derived from the opium poppy, such as heroin, in the illicit market. This high potency tends to make it very easy for people to consume more than they intend, which increases the risk of a fatal overdose.

When doctors prescribe opioid pain relievers, they measure doses using a standard metric called milligrams of morphine equivalent. This unit allows medical professionals to compare the strength and risk of different opioid drugs against a standard baseline of oral morphine. Clinical guidelines for chronic pain typically recommend keeping prescriptions below 90 milligrams of morphine equivalent per day.

In the illicit market, the lack of quality control means that people are often completely unaware of exactly how much active drug they are actually consuming. This creates significant challenges for medical professionals trying to treat opioid use disorder. Opioid use disorder is a medical condition characterized by a problematic pattern of opioid use that causes significant impairment or distress in a person’s daily life.

The research team consisted of scientists from the University of California, Los Angeles, alongside Dr. Joseph Friedman of the University of California, San Diego, and researchers from the University of Toronto. Morgan Godvin, the study’s lead author, drew inspiration for the project from her own lived experience with opioid use disorder. She recognized a massive gap between the clinical knowledge of pharmaceutical opioids and the clinical understanding of street drugs.

Free daily newsletter

“We had been treating illicit-opioid doses as a black box, an unknowable, a curiosity,” Godvin said. “Public health has precise quantification methods for other exposures, such as for tobacco or alcohol. If at the molecular level, fentanyl is fentanyl, we should be able to quantify exposure, so we decided to estimate it with the Drug Checking Los Angeles data. The results surprised us all.”

Without knowing how much fentanyl a person is accustomed to taking, it is incredibly difficult for doctors to manage withdrawal symptoms safely. It also makes it hard to prescribe effective replacement medications, such as methadone or buprenorphine, which are used to stabilize patients and reduce cravings. Medications for opioid use disorder are highly effective in reducing overdose mortality, but many patients report severe challenges starting and staying on them due to the intensity of fentanyl withdrawal.

To gather their data, the researchers utilized Drug Checking Los Angeles, a research and public health program founded by Chelsea Shover, associate professor-in-residence at the University of California, Los Angeles, and the study’s senior author. They analyzed 509 drug samples collected between September 2023 and January 2026. These samples were obtained at multiple harm reduction sites across Los Angeles County, where participants voluntarily and anonymously provided small amounts of their street drugs for chemical testing.

The scientists analyzed these samples at a national laboratory using liquid chromatography mass spectrometry. This is an advanced laboratory technique that separates, identifies, and measures the specific chemical components hidden within a complex mixture. This allowed the team to determine the exact percentage of active fentanyl hidden inside the powders and pills sold on the street.

In addition to testing the drugs, the researchers invited the individuals providing the samples to answer a confidential survey about their current drug use habits. The survey captured responses from 47 individuals who reported using fentanyl regularly over the previous thirty days. These participants provided information on how many grams of the drug they consumed daily, as well as how they administered it.

Almost all the respondents reported smoking or vaporizing the fentanyl. A smaller portion of the group reported injecting the drug, and a few reported snorting it nasally. Because the body absorbs different amounts of the drug depending on how it is taken, the researchers gathered data from previous scientific literature to estimate the absorption rate for each specific method.

Using this information, the researchers calculated the daily milligrams of morphine equivalent consumed by the participants. Because variables like drug purity, total powder consumed, and bodily absorption carry some uncertainty, the team used a complex statistical method called bootstrapping. This involved running one million computer simulated scenarios to account for all the possible variations and combinations of these factors.

The data showed that participants consumed an average of 1.07 grams of raw illicit fentanyl powder per day. When the researchers tested the actual street samples, they found that the average purity of the fentanyl was 12.5 percent. One gram of this average street product, which sells for about one hundred dollars in Los Angeles, would contain roughly 125 milligrams of active fentanyl.

“Now, we find that people are regularly exposed to doses of opioids that would have seemed impossible to me before I started this work,” Shover said. “To put it in perspective, in the hospital settings, fentanyl is often dosed in 100 microgram vials. One gram of average purity fentanyl that we tested had a dose equivalent to more than 1,200 of these vials. So people are getting daily doses that are on par with injecting hundreds of the hospital vials or taking 440 Percocet pills.”

The Centers for Disease Control and Prevention notes that for an individual without a tolerance to opioids, just two milligrams of fentanyl can be lethal. According to the study, the average consumer of fentanyl in Los Angeles takes in roughly sixty times that amount every day. Shover indicated that tolerance develops not just to the intoxicating effects of a drug, but also to the respiratory depression that leads to an overdose.

Combining the amount of powder consumed, the varying purity, and how the body processes the drug, the scientists estimated the overall daily dosage. The average daily consumption for individuals in this sample was estimated at roughly 8,888 milligrams of morphine equivalent. Even in their most restrictive statistical model, the estimated average was still above 5,000 milligrams of morphine equivalent per day.

This means that a typical consumer of illicit fentanyl is taking a dose several orders of magnitude higher than the maximum daily limit typically recommended for prescription painkillers. These findings help explain why people who use illicit fentanyl develop such extreme physical tolerance to opioids. Because the street supply is so incredibly strong, standard doses of treatment medications often fail to meet the patient’s physical needs.

“Of course, starting MOUD is going to be harder for fentanyl than it is for heroin,” Shover said, using a common acronym for medications for opioid use disorder. “This study is a great example of where our science was directly informed by lived experience. It is a call to take withdrawal management seriously, with adjuvant therapies, and compassionate approaches.”

While the data provides important insights into the modern drug crisis, the authors note a few limitations to keep in mind. The study relied on a relatively small group of 47 survey respondents from a specific geographic area that saw a later arrival of illicit fentanyl compared to the rest of the country. The individuals who voluntarily utilize drug checking services might also represent a convenience sample, meaning they could consume higher volumes of drugs than the average person and may not reflect the full range of the regional drug supply.

Additionally, there are very few sources of data about the purity of street drugs at the consumer level, with fewer than ten cities in North America currently tracking this information. The researchers also had to rely on existing scientific literature to estimate how much of the drug actually enters the bloodstream when smoked or injected. The team only measured two specific types of fentanyl, leaving out a few trace analogs that might have slightly altered the final calculations.

Because the purity of street fentanyl varies so widely, it is possible for some people to consume amounts much closer to standard medical maximums, while others consume vastly more. However, Shover noted that even if a region’s drug supply is only half as pure as what is found in Los Angeles, the resulting dosages remain dramatic. A person should not assume that every individual who uses fentanyl possesses the exact same extreme level of tolerance.

Future research will need to involve larger groups of people across different regions to confirm these consumption patterns. Gaining a more detailed understanding of how people dose themselves throughout the day will help medical professionals tailor addiction treatments to individual needs. Translating street drug usage into clinical measurements appears to be a necessary step for improving patient care, alongside implementing adjuvant therapies, which are supportive treatments given to help manage severe withdrawal symptoms.

“It’s no longer, ‘how do we treat someone who smokes a gram of fentanyl per day,’ it’s ‘how do we treat someone using thousands of MMEs of oral morphine in fentanyl per day?’” Shover said. “That question and its answers feel more accessible, less abstract to clinicians.”

The study, “Estimating the Daily Milligrams of Morphine Equivalent of Illicit Fentanyl Use in Los Angeles: Clinical and Epidemiological Implications,” was authored by Morgan Godvin, Joseph R. Friedman, Caitlin A. Molina, Adam J. Koncsol, Ruby Romero, David N. Juurlink, and Chelsea L. Shover.