Can electronic cigarettes help people stop smoking, and do they have any unwanted effects when used for this purpose?

Key messages

Nicotine electronic cigarettes (e-cigarettes) can help people to stop smoking for at least six months. They work better than nicotine replacement therapy, and probably better than e-cigarettes without nicotine.
E-cigarettes may work better than no support, or behavioural support alone, and may not be associated with serious unwanted effects.
However, we still need more evidence, particularly about the effects of newer types of e-cigarettes that have better nicotine delivery than older types, as better nicotine delivery might help more people quit smoking.

What are e-cigarettes?

E-cigarettes or 'vapes' are handheld devices that work by heating a liquid that usually contains nicotine and flavourings. E-cigarettes allow users to inhale nicotine in a vapour rather than smoke. Because they do not burn tobacco, regulated e-cigarettes do not expose users to the same levels of chemicals that can cause diseases in people who smoke conventional cigarettes.

Using an e-cigarette is commonly known as 'vaping'. Many people use e-cigarettes to help them to stop smoking tobacco. Here we focus primarily on e-cigarettes containing nicotine.

What did we want to find out?

Stopping smoking lowers the risk of many diseases. Many people find it difficult to stop smoking. We wanted to find out if using e-cigarettes could help people to stop smoking, and if people using them for this purpose experience any unwanted effects.

What did we do?

We searched for studies that looked at the use of e-cigarettes for stopping smoking in people of any age.

We were interested in:

· how many people stopped smoking for at least six months; and

· how many people had unwanted effects, reported after at least one week of use.

What did we find?

We found 80 studies including 29,861 adults who smoked. Most studies took place in the USA (40 studies) and the UK (16). Most studies compared nicotine e-cigarettes with:

nicotine replacement therapy (e.g. patches or gum);
medicines to help people stop smoking (varenicline and cytisine);
e-cigarettes without nicotine;
heated tobacco (products that heat tobacco to a high enough temperature to release vapour, without burning it or producing smoke; these differ from e-cigarettes because they heat tobacco leaf/sheet);
oral nicotine pouches (pouches that contain no tobacco but release nicotine when kept in the mouth);
other types of nicotine-containing e-cigarettes (e.g. pod devices, newer devices);
advice or counselling (behavioural support); or
no support for stopping smoking.

What are the results of our review?

More people stop smoking for at least six months with e-cigarettes than with nicotine replacement therapy (11 studies; 4114 people);
People may be more likely to stop smoking for at least six months with e-cigarettes with nicotine than e-cigarettes without nicotine (7 studies, 1918 people);
Nicotine e-cigarettes may help more people to stop smoking than behavioural support only or no support (11 studies, 7214 people);
For every 100 people using nicotine e-cigarettes to stop smoking, 8 to 10 might successfully stop, compared with only 6 of 100 people using nicotine-replacement therapy, 6 of 100 using e-cigarettes without nicotine, or 5 of 100 people having no support or behavioural support only;
We are uncertain if there is a difference between how many unwanted effects occur using nicotine e-cigarettes compared with nicotine replacement therapy, no support or behavioural support only (although non-serious unwanted effects were more common in groups receiving nicotine e-cigarettes compared to no support or only behavioural support);
Studies comparing nicotine e-cigarettes to nicotine replacement therapy reported low numbers of unwanted effects, including serious unwanted effects. Compared to nicotine e-cigarettes, there is probably no difference in how many:
- serious unwanted effects occur in people using nicotine replacement therapy;
- non-serious unwanted effects occur in people using non-nicotine e-cigarettes.

What are the limitations of the evidence?

We are confident in the evidence that nicotine e-cigarettes help more people to stop smoking than nicotine replacement therapy, but we need more evidence about e-cigarettes without nicotine.
Studies comparing nicotine e-cigarettes with behavioural or no support also showed higher quit rates in people using nicotine e-cigarettes, but we are more uncertain of the data because the people in the studies were aware of each treatment they were getting.
Most of our results for the unwanted effects could change when more evidence becomes available, as there were often few cases of effects reported with unclear results.

How up to date is the evidence?

This review updates our previous review published in 2025. We will update it again when new evidence becomes available. The evidence is up to date to 1 January 2026.

Read the full abstract

Background

Electronic cigarettes (ECs) are handheld electronic vaping devices that produce an aerosol by heating an e-liquid. People who smoke, healthcare providers, and regulators want to know if ECs can help people quit smoking, and if they are safe to use for this purpose. This is a review update conducted as part of a living systematic review.

Objectives

To examine the safety, tolerability, and effectiveness of EC for helping people who smoke tobacco achieve long-term smoking abstinence, in comparison to non-nicotine EC, other smoking cessation treatments, and no treatment.

Search strategy

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 January 2026, reference-checked, and contacted study authors.

Selection criteria

We included trials randomizing people who smoke to an EC or control condition. We included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report an eligible outcome.

Data collection and analysis

We followed standard Cochrane methods for screening and data extraction. We used the risk of bias tool (RoB 1) and GRADE to assess the certainty of evidence. Critical outcomes were abstinence from smoking after at least six months, adverse events (AEs), and serious adverse events (SAEs). Important outcomes were biomarkers, toxicants/carcinogens, and longer-term EC use. We used a fixed-effect Mantel-Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in pairwise and network meta-analyses (NMA).

Main results

We included 90 completed studies (two new to this update), representing 29,044 participants, of which 49 were randomized controlled trials (RCTs). Of the included studies, we rated 10 (all but one contributing to our main comparisons) at low risk of bias overall, 61 at high risk overall (including all non-randomized studies), and the remainder at unclear risk.

Nicotine EC results in increased quit rates compared to nicotine replacement therapy (NRT) (high-certainty evidence) (RR 1.59, 95% CI 1.30 to 1.93; I² = 0%; 7 studies, 2544 participants). In absolute terms, this might translate to an additional four quitters per 100 (95% CI 2 to 6 more). The rate of occurrence of AEs is probably similar between groups (moderate-certainty evidence (limited by imprecision)) (RR 1.03, 95% CI 0.91 to 1.17; I² = 0%; 5 studies, 2052 participants). SAEs were rare, and there is insufficient evidence to determine whether rates differ between groups due to very serious imprecision (RR 1.20, 95% CI 0.90 to 1.60; I² = 32%; 6 studies, 2761 participants; low-certainty evidence).

Nicotine EC probably results in increased quit rates compared to non-nicotine EC (moderate-certainty evidence, limited by imprecision) (RR 1.46, 95% CI 1.09 to 1.96; I² = 4%; 6 studies, 1613 participants). In absolute terms, this might lead to an additional three quitters per 100 (95% CI 1 to 7 more). There is probably little to no difference in the rate of AEs between these groups (moderate-certainty evidence) (RR 1.01, 95% CI 0.91 to 1.11; I² = 0%; 5 studies, 840 participants). There is insufficient evidence to determine whether rates of SAEs differ between groups, due to very serious imprecision (RR 1.00, 95% CI 0.56 to 1.79; I² = 0%; 9 studies, 1412 participants; low-certainty evidence).

Compared to behavioural support only/no support, quit rates may be higher for participants randomized to nicotine EC (low-certainty evidence due to issues with risk of bias) (RR 1.96, 95% CI 1.66 to 2.32; I² = 0%; 11 studies, 6819 participants). In absolute terms, this represents an additional four quitters per 100 (95% CI 3 to 5 more). There was some evidence that (non-serious) AEs may be more common in people randomized to nicotine EC (RR 1.18, 95% CI 1.10 to 1.27; I² = 6%; low-certainty evidence; 6 studies, 2351 participants) and, again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 0.93, 95% CI 0.68 to 1.28; I² = 0%; 12 studies, 4561 participants; very low-certainty evidence).

Results from the NMA were consistent with those from pairwise meta-analyses for all critical outcomes. There was inconsistency in the AE network, which was explained by a single outlying study contributing the only direct evidence for one of the nodes.

Data from non-randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued EC use. Very few studies reported data on other outcomes or comparisons; hence, evidence for these is limited, with CIs often encompassing both clinically significant harm and benefit.

Authors' conclusions

There is high-certainty evidence that nicotine EC increase quit rates compared to NRT, and moderate-certainty evidence that they probably increase quit rates compared to EC without nicotine. Evidence comparing nicotine EC with behavioural support or no support also suggests benefit, but is less certain due to risk of bias inherent in the study designs.

Overall incidence of SAEs was low across all study arms and there is now moderate-certainty evidence that SAE rates are similar when comparing nicotine EC with NRT. There was also no evidence of a difference in AEs between nicotine and non-nicotine EC nor between nicotine EC and NRT, but low-certainty evidence for increased AEs compared with behavioural support/no support. We did not detect evidence of serious short-term harm from nicotine EC, but longer, larger trials are needed to fully evaluate safety. The included studies tested regulated nicotine-containing EC; illicit products and/or products containing other active substances (e.g. tetrahydrocannabinol (THC)) may have different harm profiles.

The main limitation of the evidence base remains imprecision for some comparisons. Further RCTs are underway. To ensure the review continues to provide up-to-date information, this is a living systematic review. We run and screen searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the most recent version of this review.

Funding

Cancer Research UK (PICCTR-2024/100012). The addition of new outcomes relating to vaping and smoking at six months or more was supported by the National Cancer Institute of the National Institutes of Health (NIH) and FDA Center for Tobacco Products (CTP) under Award Number 2U54CA229974. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the Food and Drug Administration. The funders were not involved in the decision to submit for publication.

Registration

Protocol (2012) available via DOI: 10.1002/14651858.CD010216 (updates to 2012 protocol available via https://osf.io/upgjc/overview.

Citation

Lindson N, Livingstone-Banks J, Butler AR, McRobbie H, Bullen CR, Hajek P, Wu AD, Begh R, Theodoulou A, Ma C, Notley C, Rigotti NA, Turner T, Fanshawe T, Hartmann-Boyce J. Electronic cigarettes for smoking cessation. Cochrane Database of Systematic Reviews 2026, Issue 8. Art. No.: CD010216. DOI: 10.1002/14651858.CD010216.pub11.

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