Consensus is growing among researchers and public health organizations, including the National Academies of Science, Engineering and Medicine, and American Cancer Society, on harm reduction from the use of electronic nicotine delivery systems (ENDS) as compared to cigarette smoking. The US FDA Center for Tobacco Products recommends in draft guidance that human studies to support Premarket Tobacco Product Applications for ENDS include pharmacokinetic (PK) data examining the exposure to nicotine during ENDS use. Some studies indicate that experienced ENDS users reach levels of nicotine more similar to users of combustible cigarettes, albeit generally lower. In this study, selected nicotine PK measures (AUCnic 0-360, Cmax, Tmax) were investigated to assess nicotine exposure in naïve, short-term and experienced ENDS users over 6 hours with respect to the start of a 10-minute ad libitum product use period. The ENDS products were Vuse Solo Original and Vuse Solo Menthol. Data was compared to historical PK data from non-menthol and menthol cigarette smokers. Nicotine uptake (AUCnic 0-360 and Cmax) was significantly higher in both non-menthol and menthol cigarette smokers compared with Vuse Original and Vuse Menthol experienced users, respectively. Vuse Original and Vuse Menthol naïve users also had significantly lower nicotine uptake compared with experienced Vuse users. PK parameters in experienced and short-term Vuse Original and Vuse Menthol users were similar, with the exception of Vuse Original AUCnic 0-360, which was significantly higher in experienced users compared to short-term users. Tmax occurred significantly faster in the non-menthol and menthol cigarette smokers compared with the experienced Vuse Original and Vuse Menthol users. However, differences in Tmax between the experienced versus short-term or naïve Vuse users were not statistically different.