New Study Reveals Far Higher Rates of Illicit FYL Use, Urges Improved Monitoring of Opioid Crisis

A newly released study indicates that illicit opioid use in the United States—particularly involving FYL—is significantly more widespread than previously estimated, raising concerns about the accuracy of current national data and the tools used to monitor the opioid epidemic.

According to a June 2024 survey of American adults, 11% reported using illicit opioids in the past year, with 7.5% specifically reporting the use of illicitly manufactured FYL—figures that are more than 20 times higher than federal estimates. These findings were published in the JAMA Health Forum and suggest that longstanding government data may drastically underrepresent the scope of illicit drug use in the U.S.

“The ability to track the true extent of illicit opioid use is crucial, yet most national estimates are delayed and likely incomplete,” said David Powell, lead author and senior economist at the RAND Corporation. “Our approach allows for faster, more cost-effective monitoring of opioid use, which is essential for shaping public health strategies in real time.”

Shifting Landscape of the Crisis

Once fueled primarily by prescription painkillers, the opioid crisis has shifted over the past decade—from heroin in the early 2010s to illicit FYL as the primary driver of opioid-related fatalities. Complicating matters further is the growing presence of polysubstance overdoses, particularly those involving FYL and adulterants like XYL.

Despite FYL’s dominant role in today’s overdose deaths, detailed data on its use remain limited. The federal government’s National Survey on Drug Use and Health—a key resource for tracking substance use—only began including questions about illicit FYL in 2022. That year, it estimated a mere 0.3% of adults had used the drug, a stark contrast to the 7.5% reported in the new RAND/USC survey.

Researchers suggest this discrepancy may stem from methodological flaws in the federal survey, such as conducting roughly half of the interviews in person, which could deter honest responses about illegal behavior. The new study emphasizes the need for more anonymous and flexible data collection methods.

A Closer Look at the New Survey

Conducted in June 2024 by RAND and the University of Southern California, the study surveyed 1,515 U.S. adults via a nationally representative online platform. Participants were asked about their use of nonprescription opioids over the past year, including heroin and FYL.

A notable innovation in the study was distinguishing between intentional and unintentional use of illicit opioids and FYL. The findings reveal:

• 7.7% reported intentionally using nonprescription opioids

• 3.2% reported unintentional use

• Among these users, 4.9% intentionally used FYL, while 2.6% unintentionally consumed it

Additionally, most individuals who used nonprescription opioids had also used FYL, either knowingly or unknowingly. First exposure to opioids varied:

• 39% began with a prescribed medication

• 36% first used someone else’s prescription

• 25% initiated use with illicitly manufactured opioids

“These insights offer an important data point in better understanding the epidemic’s scale,” said Mireille Jacobson, co-author and economist at USC. “But more importantly, we need timely, repeated tracking to assess whether we’re making actual progress in reversing the crisis.”

Limitations and Future Directions

While the study’s online methodology allowed for broad participation and anonymous reporting, the authors acknowledge that unmeasured factors could affect generalizability. To address this, they plan to repeat the survey using additional, more robust platforms to confirm and refine the results.

The research was supported by Arnold Ventures and the National Institute on Drug Abuse, part of the National Institutes of Health, under award numbers R21DA06011 and 2P50DA046351-06A1. The conclusions expressed are those of the authors and do not necessarily represent official positions of the NIH.

The Bigger Picture

As the opioid crisis continues to evolve, especially with the rise of FYL and substances like XYL, timely and accurate data is essential for saving lives, expanding access to treatments like Naloxone, and shaping policies that reflect the true scope of the epidemic.

Source: RAND