Electronic cigarettes are more effective at helping smokers quit than traditional nicotine replacement therapies like patches or gum, according to scientific reviews and medical experts.

“It is evident from multiple studies published to date that the levels of exposure to carcinogens and oxidants sustained by vapers are very low, indicating that the risks of vaping are likely to be very small. Smokers, in particular, can remain reassured that vaping is far less harmful than smoking,” said University of Nottingham Epidemiology Emeritus Professor John Britton.

E-cigarettes or vapes are handheld devices that work by heating a liquid that usually contains nicotine and flavorings. E-cigarettes allow users to inhale nicotine in a vapor rather than smoke. Because they do not burn tobacco, regulated vapes 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."

Other smoke-free alternatives, such as heated tobacco products and nicotine pouches, also do not involve combustion, meaning they avoid the burning process that produces smoke and many of the harmful chemicals associated with smoking cigarettes.

The Royal College of Physicians (RCP) is one of the world’s oldest and most respected medical bodies, whose landmark reports have shaped UK and global public health policy, including early warnings on smoking in the 1960s.

A study published by the RCP titled “E-cigarettes and harm reduction: An evidence review” found that vapes play a significant role in preventing death, disability and inequalities caused by smoking cigarettes. The RCP said its report can be used to support more people to make quit attempts while discouraging young people and never-smokers from smoking.

The RCP report draws on extensive scientific evidence, including trials and population studies, to assess toxic exposure, health outcomes, and behavioral patterns among smokers, vapers, dual users, and non-users across multiple countries over several years.

With over 50 recommendations, the RCP report concludes that e-cigarettes remain an important tool to alleviate the burden of tobacco use.

Experts said that while stopping smoking lowers the risk of many diseases, many people find it difficult to stop. “We found evidence that nicotine e-cigarettes help more people to stop smoking than nicotine replacement therapy. Nicotine e-cigarettes probably help more people to stop smoking than e-cigarettes without nicotine, but more studies are still needed to confirm this,” the researchers said.

A review by British organization Cochrane involving 104 studies and 30,366 adults found that for every 100 people using nicotine e-cigarettes to stop smoking, 8 to 11 might successfully stop. This compares to only 6 of 100 people using nicotine-replacement therapy or e-cigarettes without nicotine and 4 of 100 people receiving no support.

The review, titled “Can electronic cigarettes help people stop smoking, and do they have any unwanted effects when used for this purpose?” concluded that nicotine e-cigarettes can help people to stop smoking for at least six months. It cites evidence showing that e-cigarettes work better than nicotine replacement therapy and probably better than e-cigarettes without nicotine. Most studies took place in the United States, with 48 studies, and the UK, with 21.

The results of the Cochrane review show that people are more likely to stop smoking for at least six months using nicotine e-cigarettes than using nicotine replacement therapy, based on 9 studies and 2,703 people, or e-cigarettes without nicotine, based on 7 studies and 1,918 people. Nicotine e-cigarettes may help more people to stop smoking than either no support or behavioral support only.

Meanwhile, a 2022 review published by Cochrane titled “How effective are medications and e-cigarettes for quitting smoking, and what works best?” also looked for randomized controlled trials.

The review looked at 332 studies that met the criteria and 319 of these provided information used in the analyses. These covered 157,179 adults who smoked tobacco cigarettes. E-cigarettes, varenicline and cytisine were most likely to help people quit smoking, according to the review.

For every 100 people, 10 to 19 are likely to quit using an e-cigarette. This compares to 12 to 16 using varenicline; 10 to 18 using cytisine; and 6 when using no medicine or e-cigarette.

“We are confident that e-cigarettes, cytisine, varenicline, nicotine replacement therapy and bupropion help people stop smoking,” the review says.