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What is Fentanyl-laced Marijuana and How Dangerous is it?

Written by Shannon Weir, RN | Updated on Apr 26, 2023

shannon weir

Medically reviewed by Shannon Weir, RN

Are people overdosing on fentanyl-laced marijuana, or do overdoses result from concurrent but separate use of marijuana and fentanyl? Until recently, health professionals and drug enforcement personnel discounted the likelihood that illegal drug manufacturers would combine marijuana with the more costly fentanyl.1 However, there is recent evidence to the contrary.

Connecticut state health officials have connected almost 40 overdoses since July 2021 to marijuana-laced fentanyl. Officials believe an overdose case in October confirmed by the Connecticut state crime lab to be the first in the nation positively identifying fentanyl and marijuana in one product.2

The Connecticut overdose patients were revived with Narcan, a drug known to reverse the effects of opioid overdose, and denied any knowledge fentanyl was in the marijuana they smoked.3

What is Fentanyl?

Fentanyl is a highly addictive, powerful synthetic opioid 50 to 100 times more potent than morphine. Doctors legally prescribe the drug to treat severe pain, especially breakthrough cancer pain. Because of its potency, there is a strong demand in the illicit drug market for prescription fentanyl, where drug dealers mix it with other drugs. By combining lower-cost fentanyl with drugs like heroin, dealers increase profits while providing a more intense high to their customers.4

Drug dealers routinely manufacture fentanyl in foreign labs, mix it with illegal drugs like heroin or cocaine, and smuggle it into the U.S.5 Customers can even obtain the drug by mail order.6 Users often die because they are unaware the product they purchased contains deadly fentanyl.

According to Centers for Disease Control and Prevention (CDC) statistics, overdose deaths from synthetic opioids, primarily fentanyl, increased by over 56 percent between 2019 and 2020. The CDC recently published provisional data suggesting COVID-19 is significantly impacting those numbers.7 New CDC statistics indicate opioid overdose deaths increased by almost 30 percent in the twelve months ending April 2021.8

Signs of Fentanyl Overdose

Fentanyl overdose is a medical emergency. If treated promptly, the drug Narcan can often reverse the overdose effects and save the person’s life. Because having Narcan readily available for those using legal or illegal opioids is critical, it is now legal in all 50 states for citizens to purchase Narcan nasal spray from a pharmacy without a prescription.9

Even with Narcan intervention, overdose victims must receive subsequent emergency medical treatment. Opioids can last longer in the body than the effects of Narcan, which means the person could return to a state of overdose.10,11

According to the CDC, signs of opioid overdose often include the following:12

  • Small, constricted “pinpoint pupils”
  • Falling asleep or losing consciousness
  • Slow, weak, or no breathing
  • Choking or gurgling sounds
  • Limp body
  • Cold or clammy skin
  • Discolored skin (especially on lips and nails)

Fentanyl and Marijuana – Are They Both Dangerous?


Fentanyl is one of the most dangerous drugs on the planet; synthetic opioids like fentanyl now contribute to twice as many deaths as heroin.13 Drug dealers mix fentanyl with other drugs like heroin because fentanyl is cheaper and much more potent than heroin, increasing dealers’ profit margins.

How does fentanyl kill? Opioids like fentanyl interfere with the brain signals that warn of low oxygen levels or high carbon dioxide levels, disrupting the respiratory response. Breathing becomes dangerously low, which can cause brain damage or coma, or breathing stops, causing death.14

Fentanyl is highly addictive, with addicted individuals compulsively seeking and using the drug despite harmful consequences. Once addicted, the person will experience withdrawal symptoms if they stop using the substance.15


Although medical marijuana is currently legal in 37 states and recreational marijuana is legal, with some restrictions in 21 states,16 that does not mean the drug is safe. Many studies have found disturbing links between marijuana and physical or mental disorders.17

A National Institute on Drug Abuse research report warns marijuana can cause severe, long-term effects, including:18,19

  • Acute psychosis, hallucinations, delusions, and a loss of personal identity
  • Impaired thinking, interfering with the ability to learn or perform complex tasks
  • Impaired driving
  • Decline in IQ, especially when use starts in adolescence

Medical News Today warns of other potential repercussions from regular marijuana use, including:20

  • Regular users are more likely to experience depression or suicidal thoughts
  • A possible link to testicular cancer and lung cancer

The CDC cites a study finding that three in ten people who regularly use marijuana have a diagnosable marijuana use disorder and cannot stop using it despite negative health, social, and other consequences, all characteristic of addiction.21

One study estimated that approximately 3 in 10 people who use marijuana have marijuana use disorder, meaning that they are unable to stop using marijuana even though it is causing health or social problems in their lives.

There is also some evidence those who use marijuana are more likely to use other drugs.22

How to Avoid Fentanyl-Laced Marijuana

Unless your doctor has prescribed fentanyl, avoid the drug at all costs. Fentanyl is the underlying cause of more deaths than any other prescription or illicit drug, including the deaths of many children who accidentally ingested the drug or absorbed it through their skin.23,24

Marijuana purchased from a legal dispensary is likely to be a quality product. Most states require third-party testing to verify THC and CBD levels and ensure purity. But if you buy marijuana or other drugs on the street, you cannot know what the product contains. Unregulated marijuana may contain contaminants like microbes, heavy metals, pesticides, or dangerous drugs like fentanyl.25

You can’t see, taste, or smell fentanyl. Fortunately, you can buy fentanyl test strips that are inexpensive and alert you within minutes whether fentanyl is present. The CDC does caution that the test strips may not detect more potent forms of fentanyl, like carfentanil.26

Although fentanyl-laced marijuana is rare, that could change as fentanyl becomes less expensive or if consumers begin to demand it.27 To protect yourself and your loved ones, educate yourself about the dangers of fentanyl and ensure it is never accessible to children or pets.

If you or a loved one has an alcohol or substance use disorder, contact Gallus Medical Detox to learn how we help our clients get their health and lives back on track.



Shannon Weir, RN

Shannon Weir, RN is the Chief Nursing Officer at Gallus Medical Detox Centers. She has been a Registered Nurse for 30 years, Shannon’s experience ranges from critical care to flight nursing, medical detox, sexual assault exams, and SWAT nursing. Shannon has been with Gallus Medical Detox Centers since 2010 and is a vital part of our organization.

Last medically reviewed on December 14, 2022

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