Several social media posts and local news reports warn of fentanyl-laced marijuana, or cannabis. While isolated case reports suggest that cannabis may sometimes contain fentanyl, most reports argue this is likely an urban legend or a very rare occurrence.

It is common for drug dealers to lace other drugs, such as prescription painkillers, with fentanyl. This is because of its comparatively low cost. However, it can intensify the side effects of other drugs and increase the risk of overdose.

Fentanyl is a leading cause of drug overdoses in the United States, and some people who overdose do not know they are using fentanyl. However, as fentanyl remains more expensive than cannabis, fentanyl-laced cannabis would not make financial sense.

The Ontario Harm Reduction Network reports that there have been no laboratory documented cases of fentanyl-laced cannabis in Canada. It emphasizes that reports claiming to have found fentanyl in cannabis often have alternate explanations or do not use scientific evidence.

Read on to learn more about fentanyl-laced cannabis, including the risks and how to avoid it.

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Fentanyl is a potent opioid that a person can only acquire through a medical prescription.

Prescription fentanyl is safe when taken as instructed under the guidance of a healthcare professional. However, illegally manufactured fentanyl is on the rise. In recent years, it has become a leading cause of drug overdoses. This often happens when a person uses fentanyl alongside other drugs, but it can also cause an overdose on its own.

As illegally manufactured fentanyl is readily available, it is also less expensive and more accessible than some other opioids. Some drug dealers now press fentanyl into pills to make it look like an opioid prescription or to increase the “high” a person experiences with other opioids.

Several media reports now also claim that drug dealers lace cannabis with fentanyl. Very little evidence supports this claim.

A 2020 case report details the story of a 50-year-old male seeking treatment for opioid use disorder. His urine screens continued to test positive for fentanyl, but he claimed only to be using cannabis. This suggests he may have been using fentanyl-laced cannabis. When he stopped using cannabis, his urine stopped testing positive for fentanyl.

However, the man had a history of opioid use and might have been using fentanyl as an alternative source of opioids rather than using fentanyl-laced cannabis.

Several advocacy organizations and experts say that the notion of fentanyl-laced cannabis is a hoax or myth. At its 2022 conference, for example, the Journal of Emergency Medical Services called fentanyl-laced cannabis a myth promoted by the media and law enforcement.

Stories of fentanyl-laced cannabis often provide little support for their claims. The Ontario Harm Reduction Network in 2019 emphasized that many such stories involve no scientific testing and that cannabis in Canada has never tested positive for fentanyl.

Instead, stories of people overdosing on fentanyl while using cannabis might be because a person uses opioids while they use cannabis.

Learn more about fentanyl here.

Lacing any drug — including cannabis — with fentanyl increases the risk of an overdose. Fentanyl is an extremely potent opioid. It is 100 times stronger than morphine. This means that even a small quantity of fentanyl can lead to an overdose, especially if a person is using other drugs simultaneously.

The signs of an overdose include:

Some other risks of fentanyl use include:

Additionally, using fentanyl frequently — even accidentally — can cause a person to become physically dependent on it, which could lead to addiction. This can cause opioid withdrawal symptoms if they stop using fentanyl or the drug containing it. Withdrawal can make a person very ill and can be dangerous if a person is pregnant or has underlying health conditions.

Some symptoms of opioid withdrawal include:

There is no way for a person to tell the difference between pure cannabis and cannabis laced with fentanyl just by looking. The most reliable method is to use fentanyl test strips, which can reliably detect the presence of fentanyl.

Whether fentanyl-laced cannabis is real or common remains the subject of controversy. As fentanyl is more expensive than cannabis, it is unlikely that a person will routinely encounter cannabis with fentanyl.

However, Narcan is a drug to treat opioid overdose and can save a person’s life. Carrying it is beneficial for anyone who has concerns about overdose. The high opioid overdose rate means it is possible for anyone to encounter a person who has overdosed.

Some other safety strategies include:

  • Find a legal way to purchase cannabis: If cannabis is illegal in a person’s home state, they might travel to a nearby state to buy the drug.
  • Quit using cannabis and replace with a legal drug: This is the only surefire method for avoiding contaminated cannabis.
  • Avoid using drugs alone, especially when a person buys from a new provider for the first time.

Seeking help for addiction may seem daunting or even scary, but several organizations can provide support. If you believe that you or someone close to you is struggling with addiction, you can contact the following organizations for immediate help and advice:

Fentanyl-laced cannabis may not be real. If it is, it is likely rare due to the financial disincentive to add expensive fentanyl to comparatively more affordable cannabis. However, as fentanyl becomes more affordable, this could change.

People who have concerns about fentanyl-laced cannabis can reduce their risk by buying legal cannabis and eliminate the risk by avoiding cannabis. Otherwise, harm reduction strategies, such as buying from the same drug dealer each time, may help.

People who are concerned may wish to consider carrying Narcan, which treats opioid overdose.