Latest Cochrane Review finds high certainty evidence that nicotine e cigarettes are more effective than traditional nicotine replacement therapy (NRT) in helping people quit smoking Cochrane A scoping review of studies on the health impact of electronic nicotine delivery systems Internal and Emergency Medicine Springer Nature Link Graphical review: The redox dark side of e cigarettes; exposure to oxidants and public health concerns ScienceDirect E cigarettes: How they work, risks, and research