One of the deadliest street drugs, illicit fentanyl, has transitioned from a hidden killer that people often hope to avoid to one that many drug users now seek out on its own.
The shift to intentional use of fentanyl underscores a worrying trend in the country's ongoing opioid epidemic, experts say: That a growing number of people have become so tolerant to opioids like heroin, that they're turning to the synthetic compound, which is up to 50 times stronger.
Until recently, intentional use of fentanyl was mostly limited to the West Coast, but in the past few years, addiction specialists have seen an uptick in use of the drug across the country.
"Two years ago, I would have thought this was crazy," said Dr. Akhil Anand, a psychiatrist at the Cleveland Clinic who specializes in addiction. Now, Anand said, he's seeing a lot more people in Ohio seeking out illicit fentanyl as their drug of choice.
In medical settings, fentanyl is used to treat patients in severe pain, such as people just out of surgery. Fentanyl skin patches are sometimes prescribed for severe pain for use at home.
But fentanyl first made its way into the illicit drug supply about 10 years ago, particularly in areas east of the Mississippi River. The white powder looked just like heroin, but was much cheaper. Drug dealers started mixing the two drugs as a way to stretch their heroin supply. Fentanyl also started showing up in non-opioid drugs, such as cocaine and fake versions of prescription pills.
The shadowy addition of fentanyl to the illegal drug supply sent deadly overdoses skyrocketing among users who were unaware they were using such a strong drug. By 2021, fentanyl was involved in the vast majority of overdose deaths, according to the National Center for Health Statistics.
Mary Ward, president of the McLeod Addiction Center in Charlotte, North Carolina, has noticed the shift toward a preference for fentanyl in her home state. "Some people thought they were buying heroin on the street, and it turned out to be fentanyl," Ward said. "They ended up liking it better."
Alex Kral, a Berkeley, California-based epidemiologist who studies illicit drugs at the nonprofit research institute RTI International, said he's heard from users that once they start using fentanyl, it's very tough to go back to using heroin, because they don’t get the same high.
What's more, experts said, people are increasingly moving from injecting fentanyl to smoking it.
"My prediction would be that smoking fentanyl will be the norm within a year" among those who use the drug on its own, said Dr. Daniel Ciccarone, a professor of family community medicine at the University of California, San Francisco.
Ciccarone said that the shift from injecting to smoking could be seen as a form of harm reduction, in that it eliminates the risk of infections spread through shared needles, including HIV, hepatitis C and bacteria that can cause heart infections.
"It’s nice to not have to use your veins or not inject, and so a lot of people would prefer not to be doing that," Kral said. "I think we're going to see more and more people smoking fentanyl than injecting it."
Others were concerned that because smoking fentanyl is easier and often more appealing than injecting it, it could result in more widespread use. And there's no data to suggest that smoking fentanyl reduces the risk for fatal overdoses.
"I don't know that we're at a place where we can say, 'Hey, maybe you should smoke it instead,'" said Dr. Kris Kast, clinical director of the Addiction Consult Service at Vanderbilt University Medical Center in Nashville. "It would be hard for me to feel confident in recommending that to somebody."
While fentanyl overdoses can be reversed with naloxone, the high potency of the drug means more naloxone is needed to counteract it, both Anand and Ward said.
The drug also causes a shorter-lived high than other opioids, meaning users must take the drug more frequently to avoid withdrawal.
"Usually by the time somebody is transitioning to fentanyl, they're already needing to use pretty consistently throughout the day to feel normal, to not be in withdrawal," Kast said. "As they're progressing to fentanyl, they're gonna have to use it more often in order to manage that withdrawal."
And for fentanyl users receiving treatment for their addiction, doctors must prescribe higher doses of medications like suboxone and methadone to control their withdrawals.
"Because fentanyl is so powerful, patients are having greater physical withdrawals," Ward said. "We've seen an uptick in the amount of medication we've had to prescribe for some patients just to keep them stable."