//A Cochrane review

Generally seen as the gold standard for scientific evidence, an international Cochrane review analysed 50 studies in 12,430 adults (taking place in the USA (21 studies), the UK (9), Italy (7), Australia (2), New Zealand (2), Greece (2), and one study each in Belgium, Canada, Poland, South Korea, South Africa, Switzerland and Turkey).It shows [1] e-cigarettes do help people to transition away from smoking (even among those who do not intend to quit smoking) and work better than Nicotine Replacement Therapies (NRTs) or willpower alone and [2] and are not associated with serious unwanted effects or harm with up to 2 years of usage.