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Study suggests injecting fentanyl poses more health risks than smoking it

People who inject fentanyl are 40 percent more likely to have overdosed compared to people who report only smoking the synthetic opioid

RESEARCH TRIANGLE PARK, N.C. — A new study from experts at RTI International, a nonprofit research institute, has found that people who inject illicit fentanyl, as opposed to smoking it, are 40 percent more likely to have overdosed and 253% more likely to have had a skin or soft tissue infection. It is the first study to report associations between different methods of fentanyl administration and health and health care outcomes in the U.S.

“Our findings suggest that with regards to method of fentanyl administration, injection is associated with more health complications than smoking,” said Barrot H. Lambdin, Ph.D., an epidemiologist and implementation scientist at RTI who led the study. “People who currently inject fentanyl would seemingly reduce their odds of overdosing, and potentially fatally overdosing, by switching to smoking.” 

The method of administration did not significantly impact emergency department utilization, the researchers found, but people who injected fentanyl spent significantly more nights in the hospital on average.

To conduct the study, the research team recruited 999 people who use drugs from 34 syringe services programs across California and surveyed their substance use, health outcomes, and health care utilization in the preceding three months. Among the 563 people who reported using fentanyl, they compared health risks among the 41% of people who injected fentanyl (78% of whom also smoked) to the 59% who solely smoked fentanyl.

Lambdin and his colleagues note that the distribution of safe smoking supplies via syringe services programs and safe consumption sites could help people transition from injecting to smoking, thereby reducing their risk of overdose and skin or soft tissue infection. By distributing safe smoking supplies, syringe services programs may also reach a broader population at risk for overdose, not just people who inject drugs, they write.

The study comes as policymakers devote attention, funding, and services to reduce overdose deaths from fentanyl. The research team was the first to document a transition to smoking fentanyl in San Francisco from 2018 to 2020. The transition to smoking fentanyl has become common on the West Coast and is now starting to occur in the eastern U.S. Beginning in 2016, fentanyl became the most common drug detected in drug overdose decedents in the U.S., according to past research. In 2021, 75% of drug overdose deaths involved an opioid, according to the Centers for Disease Control and Prevention. 

The study was funded by the California Department of Public Health and published in the peer-reviewed scientific journal Drug and Alcohol Dependence

View the full study

Learn more about RTI’s substance use research