Abstract
Electronic nicotine delivery systems (ENDS; i.e., electronic cigarettes, e-cigarettes, vaping devices, vape pens) were introduced to the U.S. market in 2007 as a potential harm reduction alternative for people who smoked combustible cigarettes. Since that time, ENDS popularity grew very quickly, particularly among individuals who smoke cigarettes. However, young people and never smokers also started using ENDS, cohorts for whom these products were not intended. There are now a broad range of devices and e-liquid constituents. ENDS devices vary considerably in their design and generation of potentially toxic chemicals, with higher power devices likely much more hazardous than lower power devices. This landscape may further change after September 9, 2020, when all ENDS manufacturers are required to submit a premarket tobacco product application to the FDA to obtain authorization for marketing. Research has not kept pace with this rapidly changing technology and important questions remain regarding the relative benefits versus risks of ENDS. In light of these challenges, we propose key ENDS research priorities to address these gaps.