What are the results of our review?
More people probably stop smoking for at least six months using nicotine e-cigarettes than using nicotine replacement therapy (3 studies; 1498 people), or nicotine-free e‑cigarettes (3 studies; 802 people).
Nicotine e-cigarettes may help more people to stop smoking than no support or behavioural support only (4 studies; 2312 people).
For every 100 people using nicotine e-cigarettes to stop smoking, 10 might successfully stop, compared with only six of 100 people using nicotine-replacement therapy or nicotine-free e-cigarettes, or four 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 using nicotine-free e-cigarettes, nicotine replacement therapy, no support or behavioural support only. Similar low numbers of unwanted effects, including serious unwanted effects, were reported for all groups.
The unwanted effects reported most often with nicotine e-cigarettes were throat or mouth irritation, headache, cough and feeling sick. These effects reduced over time as people continued using nicotine e-cigarettes.
How reliable are these results?
Our results are based on a small number of studies, and in some the measured data varied widely.
We are moderately confident that nicotine e-cigarettes help more people to stop smoking than nicotine replacement therapy or nicotine-free e-cigarettes. However, these results might change if further evidence becomes available.
We are less confident about how nicotine e-cigarettes compare with no support, or behavioural support, to stop smoking.
Our results for the unwanted effects are likely to change when more evidence becomes available.
Nicotine e-cigarettes probably do help people to stop smoking for at least six months. They probably work better than nicotine replacement therapy and nicotine‑free e-cigarettes.
They may work better than no support, or behavioural support alone, and they may not be associated with serious unwanted effects.
However, we need more, reliable evidence to be confident about the effects of e-cigarettes, particularly the effects of newer types of e-cigarettes that have better nicotine delivery.
The Cochrane review is now a living review every 6 months, and is updated to inform on the latest results!
The living review can be found here