A synthetic drug more than 40 times stronger than fentanyl has infiltrated the US drug supply, with federal data estimating more than 2,000 Americans have already been killed.

Nitazenes are a group of compounds developed in the 1950s as an opioid pain reliever, but they never made it to patients because of the extremely high risk of overdose. In addition to being stronger than fentanyl, it’s about 100 times stronger than morphine.

However, recently, the illegal lab-made compounds are increasingly being pressed into counterfeit pills that buyers believe are legitimate pharmaceuticals, such as Xanax or oxycodone.

What they might not know is that nitazenes have been found in at least 4,300 law enforcement-led drug seizures since 2019. They are often mixed in with other counterfeit or illegal drugs, including opioid pills, heroin, fentanyl and methamphetamine.

Earlier this year, 22-year-old Lucci Reyes-McCallister died after taking what he believed was a Xanax pill. 

The Texas native had no idea the fake medication was laced with a type of nitazene 25 times deadlier than fentanyl. 

Just six months later, his friend Hunter Clement, 21, suffered the same fate after swallowing a counterfeit Percocet containing nitazenes. 

Lucci had received Narcan, the opioid overdose reversal agent, during a previous overdose in the fall, but not the second time. He was found already deceased in his apartment.

Hunter Clement, right, swallowed a counterfeit Percocet pill that was pressed with nitazenes. He died of an overdose at 21

Nitazenes were never widely used until now, with a surge leaving the CDC and law enforcement at a major disadvantage. They gained popularity rapidly starting in 2019, evading officials’ limited testing capabilities, leading to underreported overdoses.

There are dozens of analogs, or modified versions of nitazenes, that have varying levels of potency.  

Potency also varies among batches, depending on the type of nitazene analog lacing the drugs, and uneven mixing means one pill may have a lethal dose while another has barely any. 

Compared to fentanyl, the analogs butonitazene and etodesnitazene are 25 to 50 percent as strong, while isotonitazene (ISO) is five to 10 times stronger. 

The most extreme variants, N-pyrrolidino protonitazene and N-pyrrolidino etonitazene, are up to 25 times stronger and up to 43 times stronger, respectively. 

Nitazenes first appeared in the US as fentanyl, which has killed an average of 70,000 Americans annually over the past three years.

At about the same time, nitazenes appeared in Europe and the UK, where they have spread quickly and have killed nearly a thousand people. 

From 2020 to 2021, Tennessee saw a notable jump in nitazene-related deaths. It was the first cluster of deaths linked to the synthetic drug the country had seen and caught the CDC’s attention. Fatal overdoses there jumped from 10 to 42. 

Most of those deaths involved multiple substances, including fentanyl and meth. ISO drove most of the nitazene-linked deaths.

From May 2024 to 2025, Houston, Texas DEA agents reported 15 nitazene overdose deaths in people ranging in age from 17 to 59. 

Lucci Reyes-McCallister, 22, died in January after taking a fake Xanax pill laced with N-pyrrolidino protonitazene—a synthetic opioid 25 times deadlier than fentanyl

William Kimbell, the special agent in charge of the division, said: ‘We started seeing it in the Houston area, our first seizure was in 2022. 

‘And kind of the reason we’re talking now is over the last year we have seen a pretty dramatic increase in its usage in Houston and the surrounding area.’ 

Kimbell added that the agency has seen a 15 percent increase in nitazene-related overdoses in Houston and surrounding areas between November 2024 and February 2025. 

Reyes-McCallister died in the Houston area on January 26. His counterfeit Xanax had been laced with N-pyrrolidino protonitazene. 

His mother Grey McCallister told the New York Post: ‘It was the first time I’d ever heard of it.’

Clement’s mother was equally as unacquainted with the drug. 

She said: ‘I told my husband, “I feel like that could be what Hunter died from.”‘

A DEA agent in the Washington Division is shown holding a baggie of counterfeit pills that contain nitrazene

The raw chemicals to make the drugs are believed to come from China and India. Chemical companies there are able to synthesize the compounds at scale in a relatively easy process of three or four steps before the substance is smuggled to the UK, Europe and the US.

Compared to countries in Asia, Europe, South America, as well as Australia, New Zealand, and the Pacific islands, the US has the widest range of nitazene analogs and the most fatalities.

In the US, drug seizures are ticking up. The Drug Enforcement Administration has reportedly seized nitazenes more than 4,000 times between 2019 and 2024.

Andrew Renna, Assistant Port Director for Cargo Operations at JFK Airport in New York City said in May: ‘Earlier this month, we seized almost a pound of nitazene that was going to a private residence in South Carolina. It was shipped from the United Kingdom.

‘Unfortunately, here at JFK, we’re seeing xylazine and nitazenes at least a few times a week in quantities ranging from just a few grams to upwards of a pound or more.’

Nitazenes often evade detection in standard toxicology tests, allowing them to fly under the radar of public health officials and medical examiners.

Many routine drug screens do not include tests for these synthetic opioids, meaning overdoses and deaths linked to nitazenes may be misclassified or underreported. 

This lack of visibility delays public health responses, leaving communities unaware of the growing threat on their streets.

Nitazene overdose can lead to severe and life-threatening symptoms, including slow or shallow breathing, which indicates respiratory depression, a hallmark of opioid toxicity.

If a good Samaritan passing by or a law enforcement officer only has one or two doses on them, it may not be enough to save the person’s life.