- Nicotine vapes were associated with significantly higher quit rates than no vaping at multiple time points
- People using vapes also smoked fewer cigarettes per day, with consistent reductions across studies
- Evidence from randomised controlled trials was rated “high” for both quitting and reduction outcomes
- Results comparing vapes with nicotine replacement therapy (NRT) were mixed and not always statistically significant
A major new systematic review and meta-analysis has found that nicotine vapes are linked to higher smoking quit rates and reduced cigarette consumption among adults who smoke.
The study, published in the Harm Reduction Journal, analysed more than 200 studies, including 22 randomised controlled trials (RCTs), to assess how vaping affects quitting and smoking behaviour.
Its overall conclusion is: “Evidence suggests that the use of nicotine-containing e-cigarettes supports cigarette smoking cessation and reduction among individuals who smoke cigarettes regularly.”
Higher quit rates across multiple timeframes
The strongest findings come from pooled analyses of RCTs comparing people who used nicotine vapes with those who did not.
At the longest follow-up periods across studies, vaping was associated with significantly higher quit rates, with users more than twice as likely to stop smoking (RR=2.73).
This pattern held at shorter timeframes too. At six months, vape users were around 2.7 times more likely to quit (RR=2.70), and at three months the effect was even larger (RR=3.49).
The authors note that these consistent results across time points strengthen the overall evidence base, particularly as they are drawn from controlled trials rather than observational data.
Fewer cigarettes among those who keep smoking
The review also looked at what happens to people who do not quit entirely.
Across multiple meta-analyses, those using nicotine vapes reduced their cigarette consumption significantly more than those who did not vape.
At the longest follow-up, vape users smoked on average around four fewer cigarettes per day than non-users. Similar reductions were seen at one, two, three and six months.
The authors conclude that “e-cigarette use was associated with a greater reduction at all follow-up periods.”
Mixed results against nicotine replacement therapies
When compared directly with traditional stop-smoking aids such as patches or gum, the picture is less clear.
Meta-analyses comparing nicotine vapes with NRT found no statistically significant difference overall, although results tended to favour vaping.
For example, one pooled estimate suggested higher quit rates with nicotine vapes (RR=1.59), but the confidence intervals included the possibility of no difference.
The authors say the limited number of studies in these comparisons makes it harder to draw firm conclusions.
Real-world and population trends
Beyond clinical trials, the review also points to broader population-level evidence.
It highlights data showing that rising vape use has coincided with falling smoking rates, suggesting a potential “displacement” effect where smokers switch away from cigarettes.
This aligns with the wider evidence base showing that vaping is increasingly used as a quitting aid or substitute for smoking.
Strong evidence, with some caveats
The researchers rated the overall strength of evidence from RCTs as “high” for both quitting and reduction outcomes. However, they also highlight somel limitations.
These include differences in how studies define vape use, variations in products and nicotine strength, and the difficulty of separating exclusive vapers from those who continue to smoke alongside vaping.
The authors also note that longer-term data beyond one year is still limited.
What it means
Taken together, the findings suggest that nicotine vapes can play a meaningful role in helping people move away from smoking, either by quitting entirely or by reducing cigarette consumption.
While not every comparison shows a clear advantage over existing stop-smoking treatments, the overall direction of evidence points to vaping as an effective tool for harm reduction.
