fentanyl laced marijuana

As more states and communities are now moving toward a more liberal approach to cannabis use, reports of it causing harm to users—both by itself or laced with drugs—are also on the rise. The latest headline favorite: fentanyl-laced marijuana.

What is Fentanyl?

Pharmaceutical fentanyl is a synthetic opioid first developed in 1959 and introduced in the 1960s as an intravenous drug. It has been approved by the Food and Drug Administration for use as an analgesic (pain relief) and anesthetic.

There are currently seven dosage forms of fentanyl pharmaceutical products available in the market:

  • Oral transmucosal lozenges (Actiq®)
  • Effervescent buccal tablets (Fentora®)
  • Sublingual tablets (Abstral®)
  • Sublingual sprays (Subsys®)
  • Nasal sprays (Lazanda®)
  • Transdermal patches (Duragesic®)
  • Injectable formulations

Fentanyl, similar to other commonly used opioid analgesics like morphine, produces the following effects:

  • Relaxation
  • Euphoria
  • Pain relief
  • Sedation
  • Confusion
  • Drowsiness
  • Dizziness
  • Nausea
  • Vomiting
  • Urinary retention
  • Pupillary constriction
  • Respiratory depression

Fentanyl abuse

Approximately 100 times more potent than morphine and 50 times more potent than heroin as an analgesic, the US Drug Enforcement Agency is on a perpetual heightened lookout for abuse of fentanyl.

Illicitly produced fentanyl is usually sold in powder or in tablet forms, alone or in combination with other drugs. It is usually added to heroin to increase its potency, although sometimes also sold disguised as heroin—which often results in overdose deaths.

Fentanyl can be injected, snorted/sniffed, smoked, taken orally by pill or tablet, and spiked onto blotter paper. Opioid addicts also extract the gel content of fentanyl patches and then consume these by injection or ingestion.

Fentanyl or opioid overdose, in general, may result in stupor, changes in pupillary size (pinpoint pupils), cold and clammy skin, cyanosis or skin discoloration due to insufficient oxygen, coma, and respiratory depression leading to death. Opioid exposure signs also include confusion, drowsiness, dizziness, headache, anxiety, and vomiting.

According to the National Forensic Laboratory Information System, reports on fentanyl (both pharmaceutical and clandestinely produced) increased from nearly 5,400 in 2014 to over 56,500 in 2017, as reported by federal, state, and local forensic laboratories in the United States.

The Centers for Disease Control and Prevention (CDC) reported that fentanyl analogues were involved in roughly 2,600 drug overdose deaths each year in 2011 and 2012. The number dramatically increased to 31,335 in 2018. 

Is Fentanyl-laced Marijuana a real threat?

Just recently, the Michigan Poison and Drug Information Center (MiPDC) issued a warning about possible cases of fentanyl-laced marijuana, tagging it as a potentially emerging public health threat.

The center said that since June 1, there have been eight suspected cases of fentanyl-laced marijuana poisoning in out-of-state hospital emergency rooms, but these have not been laboratory-confirmed.

Aside from MiPDC, health officials in Connecticut have also issued a warning about fentanyl-laced marijuana after a rash of overdoses was recorded throughout the state, with all victims claiming they had only smoked marijuana. Officials said that in at least 39 cases of marijuana-related overdose, naloxone was used for revival. Naloxone is a medicine that rapidly reverses an opioid overdose.

Unlike in Michigan where cited suspected cases have not been laboratory-confirmed, a lab test of some of the marijuana used in one of the Plymouth cases in Connecticut confirmed the presence of fentanyl. 

Department of Public Health Commissioner Dr. Manisha Juthani said this is the first lab-confirmed case of marijuana with fentanyl in Connecticut, and possibly the first confirmed case in the United States.

The Brattleboro Police Department in Vermont reported in November that marijuana recovered from a suspected opioid overdose case tested positively for fentanyl using a presumptive field test. Three people were arrested in connection with the case. However, the police department said that when the same sample was tested in a forensic laboratory, no trace of fentanyl was found.

Just a few weeks ago, the story of two Springfield high school students getting admitted to the emergency department after having smoked marijuana laced with fentanyl spread online and caused panic among parents and the whole community. The story was later found to be fake.

In 2019, the San Francisco Police Department claimed that fentanyl-laced marijuana caused several overdoses at a 420 celebration the previous year. The Department of Public Health, which monitors the number of fatal overdoses in the city, said there were no confirmed fentanyl overdoses at Hippie Hill on 420 in 2018.

There have not been any reported deaths among the suspected cases.

Fentanyl-laced Marijuana: Law Enforcement’s Boogeyman

Although fentanyl-laced marijuana has been blamed in a couple of suspected opioid-related overdose cases in some states, there has only been one “confirmed” case in Connecticut. There is also no official data to show how common poisoning from fentanyl-laced marijuana is because users not only rarely admit they’ve encountered it, no user would also admit to mixing consuming marijuana with other drugs. Cited cases of fentanyl-laced marijuana in the past are all anecdotal reports.

“It’s a very sexy, attention-grabbing story for the media, because you get two controlled substances in one headline,” said Monica Donovan, who founded the cannabis website Heady Vermont and recently wrote a column for VTDigger.

University of California epidemiologist Dan Ciccarone said that in the panic over fentanyl being mixed in weed, “fear outweighs rational evidence.” 

“There is scant evidence for cannabis laced with fentanyl,” he said.

In reference to the Brattleboro case, state-run Vermont Forensic Laboratory director Trisha Conti said field tests are presumptive and sensitive, which means they could pick up extremely small traces of drugs, including fentanyl.

Ciccarone explained that weed that tested positive for fentanyl were tested using ultra-sensitive test strips that can detect the drug at concentrations as low as one-billionth of a gram. He said weed handled by dealers and people who might use all sorts of drugs will likely have trace amounts of fentanyl, which, he said, are “not clinically meaningful”, likening it to how studies have found US currency to be widely contaminated by cocaine. “They are not felt by the person.”

Even DEA’s own senior chemist, Jill Head, confirmed in 2019 at a National Drug Early Warning System briefing that fentanyl hasn’t shown up in marijuana seized by the agency.


Treatment providers and national experts have strongly stated they do not believe fentanyl-laced weed exists or that it is the latest drug trend. According to them, such instances — realistically speaking — would not have an obvious benefit for the dealer or user.

“The truth is,” wrote Monica Donovan in her article on VTDigger, “fentanyl-laced weed is a myth and a frequent scare tactic used by law enforcement.”

Speaking from a business perspective, she contends that fentanyl is far more expensive per gram than cannabis. Moreover, a grower gains nothing by killing their customers. “It’s just bad business, don’t you think?”

Another valid point raised by experts is that, logically, fentanyl has a really low combustion point, which means it cannot be smoked directly like or with marijuana buds.

In disputing the questionable narrative, journalist and paramedic Claire Zagorski, MSc, LP from Filter magazine said burning fentanyl with flame destroys it.

“Even if someone smoked cannabis contaminated with fentanyl, the fentanyl would not be active in the smoke,” she said. “In fact, burning drugs in an incinerator is a common way to dispose of them, both for prescription medications and for illegal drugs seized by law enforcement.”

Eliza Wheeler of the National Harm Reduction Coalition—an advocacy group that promotes the health and dignity of individuals and communities impacted by drug use— explained that people who smoke fentanyl use foil, which is not how marijuana is smoked. “You cannot put a flame directly to the drug. If you sprinkle it on a bud, it destroys the actual drug by burning it. It’s not even actually possible to get high from smoking it that way.”

For his part, Nelson Hayden, executive director of The Doorway in Keene, said that injecting the fentanyl intravenously would give the user the quickest and most powerful high, which couldn’t be done with cannabis.

Debunking myths about fentanyl in weed

Fact-checker website Snopes has tagged the reports of fentanyl-laced marijuana use as untrue, saying they are “based on faulty reporting, and no evidence suggests that its occurrence is in any way rooted in reality.”

For Claire Zagorski, people can stop worrying about fentanyl in the weed. “Let’s worry about building a safe supply, opening safe consumption sites, and promoting harm reduction programming. There are plenty of real boogeymen out there,” she said.

Fentanyl-tainted cannabis may not actually be a real threat and Is merely a staple in the rumor mill and spread by authorities to caution—if not scare — people from consuming cannabis. Regardless, we suggest you only get your weed supply from trusted and legal dispensaries to ensure product integrity. 

For guidance on the use of cannabis for treatment of qualified medical conditions, schedule an appointment with doctors of natural medicine.

If you observe someone exhibiting symptoms of fentanyl or other opioid poisoning or overdose, call 911 immediately.