After years of relentless rises in overdose deaths, the United States has seen a remarkable reversal. For seven straight months, according to federal data, drug fatalities have been declining.
Expanded treatment, prevention and education efforts are playing a role, but drug policy experts believe there is another, surprising reason: changes in the drug supply itself, which are, in turn, influencing how people are using drugs.
The fentanyl on the street is starting to become weaker. Anne Milgram, who heads the Drug Enforcement Administration, announced last week that for the first time since 2021, the agency was seeing a decline in fentanyl potency, a development she attributed to the government’s crackdown on Mexican cartels and international supply chains. Last year, seven out of 10 counterfeit pills tested in D.E.A. labs contained a life-threatening amount of fentanyl, she said, but that number has dropped to five out of 10.
Addiction experts say that other interventions contributed to the declining fatalities, including wider distribution of overdose reversal medications like Narcan; an uptick in some states in prescriptions for medication that suppresses opioid cravings; and campaigns warning the public about fentanyl-tainted counterfeit pills.
Harm reduction programs that offer sterile syringe exchanges and fentanyl test strips are also saving lives, experts note. Many treatment and support services that were shuttered during the coronavirus pandemic have become more accessible.
“They are all part of a health response to substance use that is bending the curve,” said Dr. Brian Hurley, the president of the American Society of Addiction Medicine.
But now policy and medical experts both say that shifts in the illicit drug market are a growing factor, though some of the changes also have disturbing effects.
Dr. Rahul Gupta, the director of the White House Office of National Drug Control Policy, attributed the decrease in overdose deaths in part to law enforcement efforts, including cracking down on the distribution of chemicals used to make fentanyl and other supplies that bring the drug more easily into the street supply. As a result, pure fentanyl is becoming scarcer and more expensive, he said in an interview.
“Obviously, purity has a relationship to lethality,” Dr. Gupta said.
Around the country, local officials and outreach workers are noticing a shift. “We have been seeing for a while fentanyl changing: how much fentanyl is in the supply, the kinds and the form,” said Traci Green, who leads a drug checking program in Massachusetts that collects samples from harm reduction groups and law enforcement agencies.
Some epidemiologists theorize that the growing prevalence of other drugs, sold on their own and also mixed in with fentanyl, is having an impact on how people use fentanyl itself.
Fentanyl is now often diluted with xylazine, an animal tranquilizer that can cause horrific skin ulcers, which have even led to limb amputations. But drug policy experts said that xylazine, in some cases, might also be having a lifesaving effect.
People addicted to fentanyl often need the drug numerous times a day. But xylazine can sedate users for hours. If someone consumes fentanyl mixed with xylazine, “you might not shoot another bag of fentanyl, because you’re knocked out,” said Colin Miller, a researcher at the University of North Carolina, Chapel Hill, who has been interviewing drug users in Grand Rapids, Mich., and Pittsburgh about the effects of xylazine in the street supply.
Research has found that patients admitted to emergency departments for fentanyl overdoses had less severe outcomes when xylazine was also detected.
The spread of psychostimulants such as methamphetamine and cocaine may also be playing a role, medical and law enforcement experts say. But teasing apart that impact is difficult. Research suggests that stimulants are not as acutely deadly as fentanyl, though they are still dangerous. They can lead to fatal overdoses and cause chronic cardiac damage.
A recent study showed a possible correlation in Ohio between plummeting opioid fatalities and a surge of meth in the state. One author, Dr. Daniel Ciccarone, a drug policy expert and professor at the medical school at the University of California, San Francisco, interviewed opioid users about why they were now also using stimulants.
“Person after person said that methamphetamine can either distract them or get them satiated enough in its own way that they can avoid fentanyl,” Dr. Ciccarone said. “Theoretically, less cumulative dosing of fentanyl is going to lead to less fentanyl deaths.”
Researchers note that campaigns warning about tainted drug supplies have had an impact, prompting many drug users to take more precautions.
“People come in saying, ‘I want to make sure it’s not fentanyl,’” said Chelsea Shover, an epidemiologist at the University of California, Los Angeles, who runs a community-based drug checking program. “Or sometimes we see people saying, ‘I’m pretty sure this is fentanyl, but I want to make sure there’s not other stuff in it.’”
The ways people ingest fentanyl are also evolving, some researchers have observed, though they are not yet prepared to draw conclusions about how that is affecting fatalities.
Dr. Allison Arwady, the director of the government’s National Center for Injury Prevention and Control, an arm of the Centers for Disease Control and Prevention, said that fewer users were injecting fentanyl in favor of smoking or snorting it.
That may be because they are trying to avoid the necrotic wounds that are caused by xylazine and are closely associated with injection. But it may also be related to the mistaken perception that smoking or snorting is less deadly than injection. (In fact, a recent C.D.C. study showed that while injection-related opioid fatalities had dropped, particularly on the West Coast, deaths associated with smoking the drug had risen.)
Dr. Arwady said that the move away from injection, especially among younger people, could indicate they are absorbing and reacting to the public health messaging about how shared needle use can transmit dangerous infections.
Policymakers and treatment experts say it’s important to remember that though the improvements have been significant, drug-related deaths are still alarmingly high.
According to the latest provisional data from the C.D.C., overdose deaths fell to 97,000, in the 12 months that ended in June, a welcome drop below the grim 100,000 threshold that was surpassed during the pandemic but still staggering.
There were 16,000 fewer drug-related fatalities during that time period than in the period a year earlier — a projected drop of 14.5 percent. Data suggests that in many states, nonfatal overdose rates are falling as well.
But the data also shows uneven progress among racial and ethnic groups and geographic regions. Fatal overdoses among Black Americans generally increased between 2022 and 2023, while they largely decreased among white Americans, according to a recent Georgetown University analysis of state data.
Eastern and Midwestern states saw some of the sharpest fatality drops, a possible reflection of their more seasoned responses to fentanyl, which has plagued them for years. By contrast, in five Western states, where fentanyl arrived later, overdose deaths are still rising.
Moreover, the rise in opioid treatment prescriptions is not uniform, and access to treatment is still limited, obstacles to further lowering fatality as well as overall addiction rates, the American Medical Association said in a report on the opioid crisis released on Thursday.
While the overall fatality decline is welcome news, “it comes with the risk that people will say, ‘We’re doing OK now on drug overdoses, we’re making progress,’” Dr. Arwady said.
“There are entire communities that are not seeing that progress,” she continued. “Many families continue to be impacted by it every day. So it has to remain a priority for the C.D.C. and public health across the country.”
