Super-potent synthetic opioids called nitazenes are spreading across the U.S.

In high school, Ashley Delgado dreamed of becoming a doctor and one day buying her father a Rolls-Royce. “She wanted to heal people,” said her father, James Taylor. She had a high GPA, Taylor added, and did especially well in science and Latin.

In her mid-20s, Ashley suffered a leg injury and was prescribed OxyContin. The painkiller marked the beginning of a yearslong descent through addiction — from prescription opioids to methamphetamine, then heroin, and finally, fentanyl.

With her family’s support, Ashley spent time in a rehabilitation facility in her hometown of Cleveland, and in recovery she moved into a sober living home. But on an early summer morning in 2023, Ashley’s body was found on a dead-end street just outside the city. One sandal was missing. Tucked inside her bra was a folded scrap of paper containing a tan powder. She was 29.

“I have lost my father, my grandmother — that hurts,” Taylor said. “But when you lose your child, that’s the worst thing on the planet, because they’re not supposed to go before you.”

Toxicology tests would later show a mix of substances in Ashley’s system, including protonitazene and metonitazene, powerful synthetic opioids from a little-known class of drugs known as nitazenes. Her death was ruled accidental.

Before his daughter’s fatal overdose, Taylor had never heard of nitazenes, but Centers for Disease Control and Prevention data suggest overdose deaths confirmed to have involved these drugs have risen sharply in the U.S.: Reported cases increased from 27 in 2020 to 409 in 2024. Developed in the 1950s as potential painkillers, the drugs never reached the market because they were deemed unsafe for medical use. Taylor was shocked to learn they could be up to 40 times more potent than fentanyl and 500 times stronger than heroin .

Nitazenes are predominantly sold online, both on the clear web and dark web, and are often laced into other substances to increase their potency. Experts say this puts unsuspecting users seeking more common drugs, such as oxycodone, fentanyl, or stimulants like cocaine, at risk of fatal overdoses.

Ashley Delgado, with her dog Gucci, after graduating from high school in 2012. Courtesy Bellingcat

The U.S. Drug Enforcement Agency (DEA) started tracking nitazene-related seizures around 2014, but it wasn’t until 2019 that it saw a marked increase. Since then, federal authorities have scheduled dozens of nitazenes as illegal substances, launched undercover operations, filed indictments , and imposed tariffs on China, where many of the laboratories manufacturing and supplying nitazenes and fentanyl are known to reside.

Yet, figures provided to Bellingcat by the United Nations Office on Drugs and Crime (UNODC) show the United States has reported 26 different kinds of nitazenes since 2019 — the second-highest number globally, after Canada. More than 1,100 fatalities have been confirmed through the CDC’s State Unintentional Drug Overdose Reporting System (SUDORS), but experts believe the number of Americans who have died from them since 2019 could be as high as 2,000.

Alex Krotulski, the director of the Center for Forensic Science Research & Education in Pennsylvania, told Bellingcat that deaths are underreported because nitazenes were not routinely tested for. “There are only limited forensic toxicology labs that test for nitazenes, so if a nitazene was present and the lab didn’t test for it, the number wouldn’t appear in SUDORS,” he said. “Also, for labs that do test for nitazenes, they have missed cases prior to their testing.” The most recent years for which there is CDC data, 2023 and 2024, show they were the deadliest, with 747 confirmed deaths.

In this monthslong open source investigation, Bellingcat combed through dozens of criminal court proceedings, filed national, state, and county-level freedom of information requests, and obtained scores of medical examiner reports to produce the most detailed account yet of how nitazenes are infiltrating U.S. borders and destroying lives.

The investigation found that, despite efforts to curb their spread across the country, nitazenes are proliferating online. It also shows that, by the time nitazenes reach American users, they are almost always mixed with several other drugs, including methamphetamines, cocaine and, most notably, fentanyl.

As of this year, 48 of 50 states have reported nitazene seizures.

Less fentanyl, more nitazenes

Fentanyl is by far the biggest opioid killer in the U.S. With more than a quarter of a million deaths since 2021 and about 200 fatalities a day, fentanyl is one of the country’s most urgent public health crises. But drug experts warn that nitazenes can be even more potent and are being mixed with fentanyl and other substances, creating increasingly lethal combinations.

“We’re always concerned about fentanyl being mixed in with other drugs — cocaine, meth, heroin,” said Frank Tarentino, associate chief of operations for the DEA’s northeast region. “You…