A new overview of the best available evidence worldwide for smoking cessation has found that nicotine‑containing e‑cigarettes appear to be more effective for smoking cessation than other interventions such as nicotine replacement therapy (nicotine patches, gum, lozenges, etc.) e-cigarettes with no nicotine, and behavioural support.
This ‘overview’ of systematic reviews summarises existing evidence from several systematic reviews and makes the findings more accessible. The overview pooled the evidence from fourteen systematic reviews of smoking cessation interventions from 2014 to 2023.
Findings from higher-quality reviews consistently showed greater smoking cessation with nicotine-containing e‑cigarettes than other interventions. Lower-quality reviews produced more variable and imprecise estimates. When restricted to higher-quality evidence, results consistently favoured nicotine e‑cigarettes over nicotine replacement therapy, non-nicotine e-cigarettes, and other comparators.
The overview also created an ‘Evidence and Gap Map’ (EGM) to identify gaps in the current evidence that urgently need to be filled. There are currently no high-quality systematic reviews directly comparing nicotine e-cigarettes with cytisine, bupropion, or nicotine pouches. Also, direct evidence comparing nicotine e-cigarettes with varenicline is extremely limited, with only a single small trial at high risk of bias.
The EGM also showed that current evidence of serious adverse events associated with e-cigarettes is inconclusive, and that most of the studies collected data from high-income countries. Future primary research on e-cigarettes for smoking cessation should continue to collect data on serious adverse events and expand its data collection to include low-and middle-income countries.
Lead author DrAngela Difeng Wu, Senior Researcher and Lecturer at the Nuffield Department of Primary Care Health Sciences, University of Oxford, says “We hope this overview and Evidence and Gap Map can lay to rest some claims that evidence is ‘mixed’ regarding the impacts of nicotine e-cigarettes on smoking abstinence. In fact, the evidence is clear and consistent across all of the meta-analyses we consulted: e-cigarettes are effective at helping people stop smoking.”
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For editors:
This Open Access paper is available on the Wiley Online Library from the embargo date ( https://onlinelibrary.wiley.com/doi/10.1111/add.70388 ) or you may request an early copy from Jean O’Reilly, Editorial Manager, Addiction , jean@addictionjournal.org .
To speak with lead author Dr Angela Difeng Wu, please contact her at the Nuffield Department of Primary Care Health Sciences, University of Oxford by email ( angela.wu@phc.ox.ac.uk ).
Full citation for article: Wu AD, Conde M, Butler AR, Knight E, Lindson N, Livingstone-Banks J, Hajek P, McRobbie H, Begh R, Theodoulou A, Notley C, Turner T, Zhitnik E, and Hartmann-Boyce J. Electronic Cigarettes for Smoking Cessation: An Overview of Systematic Reviews and Evidence and Gap Map. Addiction . 2026. DOI: 10.1111/add.70388.
Primary funding: This research work was funded by Cancer Research UK, Grant Number PRCPJT‐Nov22/100012.
Declaration of interests: Dr Hartmann-Boyce is paid for research consultancy from the Truth Initiative. Dr Lindson is an associate editor for Addiction . Dr. Notley has received an honorarium from Vox Media for filming a 'nicotine explainer' on the role of nicotine in addiction. All other authors report no known conflicts of interest.
Addiction is a monthly international scientific journal publishing peer-reviewed research reports on alcohol, substances, tobacco, gambling, editorials, and other debate pieces. Owned by the Society for the Study of Addiction, it has been in continuous publication since 1884.
Addiction
Systematic review
People
Electronic Cigarettes for Smoking Cessation: An Overview of Systematic Reviews and Evidence and Gap Map
27-Mar-2026
Dr Hartmann-Boyce is paid for research consultancy from the Truth Initiative. Dr Lindson is an associate editor for Addiction. Dr. Notley has received an honorarium from Vox Media for filming a 'nicotine explainer' on the role of nicotine in addiction. All other authors report no known conflicts of interest.