Electronic vaping devices (e-cigarettes or ‘vapes’) have surged in popularity in recent years. They were initially introduced as an alternative to smoking tobacco, but concerns have grown around their availability, particularly as some products use flavours and packaging that may appeal to young people.
In the UK, there has also been growing concern about illegal ‘cannabis’ vape products. These products may not contain what their packaging suggests and can pose serious health risks. In this blog, we explore the latest research into the potential dangers of illegal ‘cannabis’ vapes and how they differ from prescribed medical cannabis.
At a Glance
- Medical cannabis can be vaped by eligible patients using an appropriate medical grade vaporiser or compatible vape device, when prescribed by a specialist.
- Illegal ‘cannabis’ vapes may contain unexpected substances, including synthetic cannabinoids, which can cause serious health effects.
- Research has identified cases of people becoming seriously unwell after using these products, highlighting the importance of understanding the difference between illicit cannabis vapes and those legally prescribed for medical use.
Can You Vape Cannabis?
Some forms of prescribed medical cannabis are intended to be administered using a vaporiser. This may include prescribed cannabis flower used with an appropriate vaporiser or a prescribed cannabis vape cartridge used with a compatible device.
Vaporisation involves heating the prescribed product to release cannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD), as a vapour for inhalation, rather than burning it. Prescribed cannabis flower should not be smoked.
If you are prescribed medical cannabis, it is important to use it only as advised by your clinical team and according to the instructions provided with your prescription.
Is Vaping Cannabis Legal in the UK?
Vaping medical cannabis is legal in the UK when it has been prescribed to you and is used as directed.
In contrast, illicit cannabis vapes are illegal to possess or use in the UK.H2: What Are Illegal ‘Cannabis’ Vapes?
Illegal ‘cannabis’ vapes can include disposable vapes, e-liquids and other products that claim to contain cannabis or THC, one of the main active compounds in cannabis, but are obtained illegally rather than through a valid prescription.
Research has found that some of these products contain synthetic cannabinoid receptor agonists instead – man-made chemicals that can mimic the effects of cannabis but may affect the body differently and cause serious harm.
A recent UK study reported on seven patients who were admitted to hospital after using vaping products. Tests found that all seven had been exposed to MDMB-4en-PINACA, a synthetic cannabinoid.
What is MDMB-4en-PINACA?
MDMB-4en-PINACA is a strong, man-made chemical that acts like cannabis in the body. It was first found in Europe in 2017 and was flagged as a new concerning substance in 2018. In 2021, it was the most common synthetic cannabinoid found by the Drug Enforcement Administration in the United States.
Using too much of this chemical has been linked to various unwanted effects, including seeing or hearing things that aren’t there (psychotic symptoms) and death.
Cases of Synthetic Cannabinoids on the Rise
Recently, there have been more reports of synthetic cannabinoids, like MDMB-4en-PINACA, being found in e-liquids and vapes. But there aren’t many official reports that describe how patients are affected by these chemicals, especially with lab tests to confirm it.
In the UK, two deaths between 1997 and 2020 have been linked to vaping synthetic cannabinoids. Both of these deaths were male prisoners. In the recent study, most of the patients were young people, and none of them said they intentionally used synthetic cannabinoids. Many patients experienced symptoms for a long time, with the average hospital stay being 37 hours.
MDMB-4en-PINACA Detected in Illegal Cannabis Vapes
The study also found seven patients in hospital between February 2022 and February 2025 who were exposed to MDMB-4en-PINACA through a vaping device. Four of these patients said they were vaping THC, one said they were vaping CBD, and two just said they were “vaping” other products before they felt unwell.
All of these patients experienced unwanted effects:
- Five patients showed “unusual changes in behaviour”.
- One patient collapsed and was admitted to the hospital.
- Another patient had a seizure.
- Six patients were agitated when they arrived at the hospital, and four needed medications to calm them down.
- Four patients experienced psychotic symptoms, like hallucinations and believing things that weren’t true.
- Five patients were seen by a mental health team during their hospital stay, and two were later admitted to a psychiatric hospital.
Only one patient’s vape product was available for testing. This test found MDMB-4en-PINACA in the vape, and it was also found in the patient’s urine 11 days later.
Urine samples were tested for the other six patients:
- In three cases, MDMB-4en-PINACA was the only substance found.
- In two cases, cannabis was also detected.
- In one sample, other synthetic cannabinoids were found.
What Does This Mean for Healthcare Professionals?
The authors noted that none of the patients had a previous mental health diagnosis. They suggest that when young patients experience new mental health symptoms, healthcare professionals should ask about vaping and consider whether testing for synthetic cannabinoids may be appropriate.
Staying Safe from Illegal Cannabis Vapes
Illegal cannabis vapes are increasingly found on the UK illicit market, and research suggests these products may not always contain what their labels claim. Some products sold as containing cannabis or THC have instead been found to contain synthetic cannabinoids, which can cause serious harm.
Cannabis products obtained illegally should be avoided. In the UK, medical cannabis is legally available on prescription, and patients should only use the medication prescribed to them as directed by their clinical team.
Helping people, particularly young people, understand the risks associated with illicit cannabis vapes is an important part of reducing potential harm.