VIENNA, Austria – 29 April 2025: Vaping products were initially intended as alternatives to tobacco cigarettes, delivering nicotine via vapour[1]. Over time, they have evolved to contain a wide range of flavourings, cannabinoids, nicotine analogues (such as 6-methyl nicotine)[2] and increasingly new psychoactive substances (NPS). These developments are particularly worrying as vaping products can be mis-sold or mislabelled and may contain NPS in variable concentrations. Some products may contain highly toxic substances that can cause overdose or dependence. This poses challenges for prevention and treatment, as often little is known about NPS.[3]
Adding to the concern, these vaping products are often elaborately designed, with attractive packaging and particularly popular among young consumers.[4] Their appeal is further driven by promotion on social media platforms and accessibility, such as through vending machines.[5]
Photo I: Example of a vape product containing “semi-synthetic” cannabinoids
Credit: State General Laboratory – Cyprus.
Some countries across the globe have imposed restrictions on vaping products or have banned them partially or entirely from consumer markets.[6] The substances in vaping products may be subject to national and/or international control, with the ongoing increase in NPS requiring constant vigilance.
Intentional use of non-nicotine products is well reported in North America. In the United States, a survey was conducted, asking participants what they vaped other than nicotine. The research revealed that participants most commonly reported delta-9-tetrahydrocannabinol (THC) andcannabidiol (CBD), followed by other cannabinoids. Less common substances included amphetamines, herbal supplements, caffeine, Kratom, dimethyltryptamine, opiates, vitamins, ketamine and analogues among others.[7]
The growing availability of synthetic and “semi-synthetic” [8] cannabinoids in vaping products has become evident across various countries worldwide. These substances are frequently detected in e-liquids or vape cartridges (whether disposable or non-disposable). For example, a drug checking service from the United Kingdom recently identified the following synthetic cannabinoids in vapes thought to be THC: MDMB-4en-PINACA, 5F-MDMB-PINACA, ADB-BUTINACA and MDMB-BUTINACA.[9] Analysis of 194 vape pods from Scottish prisons found that the most common substances, other than nicotine, were synthetic cannabinoids (77 per cent) and non-synthetic cannabinoids (21 per cent). Other substances found (<5 per cent) were cocaine, steroids, benzodiazepines, heroin, ketamine, antidepressants, antipsychotics and gabapentinoids. Some pods contained multiple substances.[10] Research conducted in Eastern Denmark revealed that among 91 tested e-cigarette products, 41 per cent contained “semi-synthetic” cannabinoids, and 15 per cent contained both phyto- and “semi-synthetic” cannabinoids.[11] Similarly, testing conducted by the Health Sciences Authority of Singapore revealed vapes containing synthetic cannabinoids, methamphetamine and ketamine.
Photo II: Examples of vape products containing NPS and other drugs
Source: Health Sciences Authority Singapore.
In Australia, incidents of dependence and overdoses have been associated with nitazenes detected in refillable vape liquids. In 2024, four patients in Sydney experienced severe opioid withdrawal after discontinuing prolonged use of vapes, refilled with illicit vape liquid initially thought to be cannabinoid-containing. In these vape liquids, protonitazene was identified.[12] The presence of nitazenes in vaping products has also been reported in Europe, alongside the occurrences of dimethyltryptamine in both Europe and North America.[13]
Additionally, substances such as etomidate and its analogues (including metomidate, isopropoxate, propoxate, sec-butomidate, butomidate, CF3-etomidate and 4F-etomidate) are increasingly detected in e-liquids and toxicology cases, particularly in East and South-East Asia and rare reports from Oceania.[14]
Options for response
- Promote awareness and education for health care providers and people who use vapes from the unregulated market informing that vapes may contain undeclared substances that cause unexpected impairment, toxicity and dependence.
- Conduct surveys around vape use to collect data on substances used in vapes other than nicotine.
- Perform comprehensive laboratory testing on vapes from the unregulated market as they can contain a wide range of drugs, including NPS. The scope of analysis is informed by the UNODC Early Warning Advisory on NPS.[15]
- Establish/strengthen early warning systems to rapidly identify and respond to emerging drug threats.[16]
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[1] UNODC, World Drug Report 2024 (United Nations publication, 2024).
[2] Felix Effah and others, “Emerging nicotine analog 6-methyl nicotine increases reactive oxygen species in aerosols and cytotoxicity in human bronchial epithelial cells”, Toxicology Letters, vol. 405, pp. 9-15 (March 2025).
[3] United Nations, “What are NPS”, UNODC Early Warning Advisory on New Psychoactive Substances. Available at: https://unodc.org/LSS/Page/NPS (accessed on 28 April 2025).
[4] UNODC, World Drug Report 2024 (United Nations publication, 2024) and Carmen C.W. Lim and others, “Prevalence of Adolescent Cannabis Vaping: A Systematic Review and Meta-analysis of US and Canadian Studies”, JAMA Pediatrics, vol. 176, No. 1, pp. 42-51 (January 2022).
[5] UNODC, “Beyond plants: semi-synthetics diversify the cannabis market”. Smart Forensics Update, vol. 1 (May 2024).
[6] See for example a press release on FAQs on e-cigarettes, vaporisers and heat-not-burn tobacco products from the Government Singapore here.
[7] Alaina K. Holt and others, “Survey of U.S. Residents and Their Usage of Electronic Cigarettes with Drugs Other Than Nicotine”, Journal of Psychoactive Drugs, vol. 56, No. 4, pp. 568-577 (August 2023).
[8] See United Nations Office on Drugs and Crime (UNODC), “November 2024 – UNODC EWA: New Evolution of “semi-synthetic” cannabinoids”, news clip, November 2024.
[9] WEDINOS, “Sample results”, drug checking sample database. Available at: https://wedinos.org/sample-results (accessed on 10 April 2025).
[10] Victoria Marland, Leverhulme Research Centre for Forensic Science, University of Dundee, “Detection of illicit drugs in seized vape pods from Scottish prisons”, presented at TIAFT Continuing Education Committee Webinar: Exploring the Evolution and Detection of Alcohol & Illicit Drugs in Vaping Devices, 25 March 2025.
[11] Christian F. Jørgensen and others, “Emergence of semi-synthetic cannabinoids in cannabis products seized in Eastern Denmark over a 6-year period”, Journal of Forensic Sciences, vol. 69, No. 6 (November 2024).
[12] Australia, NSW Health, “UPDATED: Cases of dependence and overdose linked to nitazenes (strong opioids) in refillable vape liquids”, Safety Notice 023/24, 26 August 2024 and Rebekka Syrjanen and others, “Protonitazene detection in two cases of opioid toxicity following the use of tetrahydrocannabinol vape products in Australia”, Clinical Toxicology, vol. 62, No. 8, pp. 539-541 (August 2024).
[13] United Nations, UNODC Early Warning Advisory on New Psychoactive Substances (EWA), Database (accessed on 10 April 2025) and Alaina K. Holt and others, “Survey of U.S. Residents and Their Usage of Electronic Cigarettes with Drugs Other Than Nicotine”, Journal of Psychoactive Drugs, vol. 56, No. 4 (August 2023), p. 568-577.
[14] For further information, please see: United Nations Office on Drugs and Crime (UNODC), “March 2025 – Increasing detections of etomidate and analogues on illicit drug markets is becoming a global concern”, news clip, 4 March 2025; Yiling Tang and others, “Metabolic Profile of Etomidate and Its Three Analogs in Zebrafish, Human Liver Microsomes, Human Urine and Hair Samples Using UHPLC-Q Exactive Orbitrap-HRMS”, Drug Testing and Analysis (February 2025); and Hui Yan,Academy of Forensic Science, China, “Etomidate and Its Analogs in Vaping-associated Forensic casework”, presented at TIAFT Continuing Education Committee Webinar: Exploring the Evolution and Detection of Alcohol & Illicit Drugs in Vaping Devices, 25 March 2025.
[15] For further information, please find here relevant publications for drug testing laboratories of the UNODC Laboratory and Scientific Services Section.
[16] For further information, please see: UNODC, The role of drug analysis laboratories in Early Warning Systems (June 2020).