They are designed to help smokers quit their habit, but according to new research, e-cigarettes actually leave users more nicotine dependent.
In a study by researchers at the Memorial Sloan Kettering Cancer Centre in New York City, cancer patients who used the electronic gadgets to help them quit smoking were found to be more addicted than those still buying cigarettes.
A total of 1,074 cancer patients took part in the research, and each was enrolled into a tobacco treatment programme between 2012 and 2013.
During that time there was a three-fold increase in the use of e-cigarettes in patients, and those using the gadgets were not only more hooked than non-users, they also had more prior quit attempts under their belts, and were more likely to be diagnosed with lung, head or neck cancers.
Furthermore, e-cigarette users were found to be just as likely as non-users to continue smoking, with seven-day abstinence rates 44.4 percent among e-cig users, compared to 43.1 per cent for cigarette smokers.
The findings, which were published in the journal Cancer, have given rise to doubts over whether e-cigarettes are a viable stop-smoking aid, or in fact hinder attempts to quit.
Dr Jamie Ostroff, who led the study, emphasised that further research was necessary to "evaluate the potential harms and benefits" of e-cigarettes as a quit smoking aid, but advised that oncologists should refer patients for other cessation methods such as counselling or medication, and "provide education about the potential risks and lack of known benefits of long-term e-cigarette use".
Are you an e-cigarette user? Do you believe they will help you to eventually quit smoking, or are you more addicted than ever? Leave your comments below...