Mexico’s drug cartels are using homeless people as human guinea pigs to test experimental cocktails of fentanyl — with deadly consequences.
Gang members visit camps in northwest Mexico and offer broke addicts sums of around $30 to try an injection of their latest fentanyl concoction — and then watch to see what happens next.
The gangsters, who visit such camps on a daily basis, use their cell phones to document the reactions to their powerful synthetic opioids, an investigation by The New York Times shows.
Homeless camp resident Pedro López Camacho is among those who took the money, and the needle, several times. He survived but says he watched others take their last breaths after getting a shot.
‘When it’s really strong, it knocks you out or kills you,’ he said. ‘The people here died.’
The testing on human guinea pigs marks the latest phase in an opioid abuse crisis that began in the US in the late 1990s and saw overdose deaths spiral, climbing at times by more than 30 percent a year.
Fatalities peaked in the US at more than 110,000 in 2022, says the Centers for Disease Control and Prevention.
Deaths fell back to 97,000 in the 12-month period ending in June 2024.
The shift is attributed to greater public awareness of the dangers of fentanyl, more addiction treatment, the availability of opioid reversal drugs — and because so many addiction-prone people have already perished.
Even so, the fatality rate remains shockingly high, and president-elect Donald Trump has said he’d ‘like to end the drug epidemic’ by battling the multi-billion dollar cartels bringing drugs into the US.
He’s vowed to crack down on fentanyl smugglers, secure the US-Mexico border, execute drug dealers and pressure China into halting the export of the pre-cursor chemicals in fentanyl.
His incoming administration’s border czar, Tom Homan, a former Immigration and Customs Enforcement chief, has threatened military action against Mexican cartels and the ‘full might of the United States special operations to take them out.’
The gang members who test new variations of fentanyl on the impoverished show how the groups are adapting to a fast-changing environment and how far they will go to dominate the US market.
Global efforts to crack down on synthetic opioids have in recent months made it harder for them to source the chemical compounds needed to produce fentanyl.
The original source, China, has restricted exports of raw ingredients, pushing gang bosses to devise new and risky ways to maintain fentanyl production and potency.
They’ve started mixing the drug with a wider range of additives — including animal sedatives and other potent anesthetics. To test their results, the criminals who make the fentanyl for the cartels, known as cooks, say they inject their experimental cocktails into humans as well as chickens and rabbits.
If the rabbits survive beyond 90 seconds, the drug is seen as too weak to be sold in the US.
After raiding cartel labs, officials have described finding dead animals used for testing among the drug-making gear.
‘They experiment in the style of Dr. Death,’ Renato Sales, a former national security commissioner in Mexico, told The Times.
‘It’s to see the potency of the substance.’
Cooks described trying out unusual drugs — including oral anesthetics and canine sedatives — in the quest for a viable fentanyl mixer.
The labs are haphazard. Cooks mix up vats of chemicals using rudimentary gear, exposing themselves to toxic substances that have left some hallucinating, retching, passed out and even dead.
The cartel cooks of Sinaloa State are credited with introducing xylazine, an animal tranquilizer known on the street as ‘Tranq,’ to the US drug market. It’s often mixed with fentanyl into a deadly cocktail.
‘You inject this into a hen, and if it takes between a minute and a minute and a half to die, that means it came out really good,’ a cook told the paper.
‘If it doesn’t die or takes too long to die, we’ll add xylazine.’
Experts say that more potent combinations net more money for the cartels.
Caleb Banta-Green, a research professor at the University of Washington School of Medicine, called it a ‘wild west of experimentation.’
The cartels are recruiting university chemistry students as their cooks.
One student hired by the cartel revealed that to test new cocktails, the group brought in drug users living on the street and injected them with synthetic opioids.
No one has died, said the student, but some were left convulsing and foaming at the mouth.
The cooks responsible for mistakes are severely punished by angry cartel bosses.
Armed men have reportedly locked offenders in rooms with rats and snakes and left them there for long stretches without food or water.
After a human guinea pig dies from a drug test, cartel chiefs still greenlight the mixture for export to the US.
A powerful and potentially lethal batch of fentanyl can be attractive to users in the US, as it is certain to get them high.
‘One dies, and 10 more addicts are born,’ a cartel chief told The Times. ‘We don’t worry about them.’
US health chiefs have recently started warning about a drug 100 times more potent than fentanyl that’s claimed lives across 37 states in recent years.
The drug, called carfentanil, is a derivative of fentanyl that was designed to tranquilize elephants.
It’s the most potent commercial opioid on the market.
There were 513 overdoses from carfentanil between January 2021 and June 2024, hitting states like Florida and West Virginia the hardest, says a CDC report from December.
It comes in powder, paper, tablet, patch and spray form, and can be inhaled, ingested or absorbed through the skin.
In it’s powdered form, the drug mimics cocaine or heroin, and is often mixed into other illegal drugs like xylazine or counterfeit pills.
The groundwork for the US fentanyl epidemic was laid more than 20 years ago, with aggressive over-prescribing of the synthetic opioid oxycodone.
Fentanyl was originally developed in Belgium in the 1950s to aid cancer patients with their pain management.
Given its extreme potency it has become popular amongst recreational drug users.
Overdose deaths linked to synthetic opioids like fentanyl jumped from nearly 10,000 in 2015 to nearly 20,000 in 2016 – surpassing common opioid painkillers and heroin for the first time.
And drug overdoses killed more than 72,000 people in the US in 2017 – a record driven by fentanyl.
It is often added to heroin because it creates the same high as the drug, with the effects biologically identical. But it can be up to 50 times more potent than heroin, according to officials in the US.
In the US, fentanyl is classified as a schedule II drug – indicating it has some medical use but it has a strong potential to be abused and can create psychological and physical dependence.
As US authorities clamped down on its prescription, users moved to heroin, which the Sinaloa Cartel happily supplied.
But making its own fentanyl — far more potent and versatile than heroin — in small, easily concealed labs was a game changer.
The cartel went from its first makeshift fentanyl lab to a network of labs concentrated in the northern state of Sinaloa in less than a decade.
A single cook can press fentanyl into 100,000 counterfeit pills every day to fool Americans into thinking they’re taking Xanax, Percocet or oxycodone.
The pills are smuggled over the border to supply drug addicts across the US, including the homeless users seen stumbling around on the streets of San Francisco, New York and other big cities.
Fentanyl is so cheap to make that the cartel reaps massive profits even wholesaling the drug at 50 cents per pill, investigators say.
The drug’s potency makes it particularly dangerous.
The narcotic dose of fentanyl is so close to the lethal dose that a pill meant to ensure a high for a habituated user can easily kill a less experienced person taking something they didn’t know was fentanyl.
Synthetic opioids — mostly fentanyl — now kill more Americans every year than died in the Vietnam, Iraq, and Afghanistan wars combined.
In Los Angeles, San Francisco, New York and other big cities, the sight of homeless people collapsed on sidewalks, puffing fentanyl smoke and lurching from moments of slumber to bouts of violent shivering have become all too common.
The Facebook group Lost Voices of Fentanyl has tens of thousands of members who pay tribute to their loved ones whose lives were claimed by the drug.