INTRODUCTION

There is much debate over the impact of using electronic nicotine delivery systems (ENDS) on cigarette smoking trajectories, with numerous studies concluding ENDS use may aid smoking cessation^1,2 and others suggesting ENDS use may sustain dual use or inhibit quitting^3,4. Understanding of the long-term outcomes of ENDS use on cigarette smoking can ensure future scientific and policy recommendations that are in the best interest of public health.

Many studies examining the impact of ENDS use on smoking cessation focus on ENDS use in general⁵ or on one specific ENDS product⁶, and therefore do not compare the impact of similar ENDS models from different brands. However, some recent research highlights differences in user characteristics, reasons for use, or usage patterns by ENDS brand or model^7-9, indicating a need to understand the impact of use of comparable products on subsequent cigarette smoking outcomes. If one product is more effective at promoting smoking cessation and its users differ sociodemographically, some populations may be differentially impacted, with implications for health equity. A recent study found Juul and Puff Bar were more often reported as the usual brand for Black and Hispanic youth and young adults than by those of other races and ethnicities⁸. Another study noted ENDS device type differences between female and male ENDS users⁹. Still other recent findings indicate those who have smoked cigarettes in the past year who regularly use Juul were less likely to not be currently smoking, were younger, and more likely to identify as a racial or ethnic minoritized group than those who regularly use Vuse Alto⁷. Longitudinal studies following users of similar ENDS products who currently or recently smoked cigarettes are necessary to understand the ultimate effects of dual use on cessation.

This study examines differences in sociodemographic characteristics and usage patterns of leading ENDS products Juul and Alto, and measures cigarette smoking abstinence after one year among those who currently or recently smoked cigarettes at baseline. We aim to determine whether regular usage of two comparable ENDS products is associated with differential smoking outcomes at follow-up at 12 months, in interaction with or independent of sociodemographic or behavioral characteristics.

METHODS

RESULTS

Nearly two-thirds of the sample (62.4%) were smoking abstinent at follow-up at 12 months, including 40.0% of people who currently smoked at baseline. Adjusting for all covariates, there was no difference in the odds of smoking abstinence between Juul versus Alto users (Table 1, Model 1). However, interaction analyses indicated that this association differed according to age and baseline smoking status. Juul use was positively, albeit non-significantly associated (vs Alto use) with smoking abstinence among those aged ≥30 years (AOR=1.34), whereas it was negatively, albeit also non-significantly associated with smoking abstinence among young adults (aged 18–29 years) (AOR=0.20) (Model 2b). Among those who were currently smoking cigarettes at baseline, there was no significant difference in smoking abstinence between Juul and Alto users; whereas among those who were past year but not currently smoking at baseline, Juul users were more likely than Alto users to have remained abstinent at follow-up at 12 months (AOR=7.07) (Model 3b). No other interaction effects were statistically significant (Models 4–12).

Younger adults (aged 18–29 years) (AOR=3.64), those identifying as non-Hispanic White (AOR=3.03), not currently smoking at baseline (AOR=20.25), using their product (Juul or Alto) to quit smoking (AOR=2.77), or smoking menthol cigarettes (AOR=2.54) were each more likely to be smoking abstinent at follow-up at 12 months than their respective counterparts, adjusting for all other covariates (Table 1, Model 1). No significant differences in smoking abstinence were observed for gender, education level, sexual orientation, serious psychological distress, nicotine concentration, Juul/ Alto flavor, or days used per month when adjusting for other covariates.

DISCUSSION

In July 2025, the US FDA authorized marketing of Juul, which joined Alto and a limited list of other ENDS products as authorized for sale in the US¹¹, after retracting a prior market denial order for Juul¹². Understanding differences in cigarette smoking outcomes between Juul and Alto, two US market-leading brands, could inform consumers, health researchers and practitioners, and regulators. This novel study compares smoking outcomes between adults who used Juul versus Alto using longitudinal data.

Prior cross-sectional research found differences in readiness to quit, use of ENDS to quit smoking, and sociodemographic characteristics between those who use Alto versus Juul. The study reported that those who smoke cigarettes and use Alto might have greater success in subsequently quitting smoking⁷. Moreover, while Juul and Alto are both similarly designed closed-system pod ENDS with similar levels of nicotine concentration in a nicotine-salt formulation, Alto may generate greater nicotine yields¹³. However, the current prospective cohort study found no overall differences in smoking abstinence at follow-up at 12 months between those who regularly used Juul and those who regularly used Alto at baseline. Yet among those who smoked in the past year but not currently at baseline, participants were more likely to be abstinent 12 months later if they regularly used Juul than if they regularly used Alto. This suggests that those who formerly smoked who use Juul are less likely to subsequently relapse to smoking than former smokers who use Alto. However, our results indicate tentative evidence that this pattern might not extend to younger adults. Specifically, we found younger adults who regularly used Juul might be at a relative disadvantage compared to those who used Alto based on an age by Juul versus Alto use interaction. Despite this interaction, the statistical effect for Juul versus Alto was non-significant among both younger adults and adults aged >29 years, suggesting that this study may be insufficiently powered to detect a difference for one or both age groups. Further research with larger samples will be needed to reconcile these findings.

While randomized controlled trials have supported the efficacy of newer generation ENDS for smoking cessation, longitudinal observational studies have been mixed^1,14. More than three-fourths of our sample reported they were using Juul or Alto to abstain from smoking at baseline, and 62.4% were self-reported abstinent from smoking at follow-up. However, this study was not designed to evaluate the efficacy or effectiveness of Juul or Alto for smoking cessation, and generalization of findings is limited by the convenience sample and lack of biochemical verification of smoking abstinence.

Interestingly, this study found those who smoked menthol cigarettes were more likely to be abstinent at follow-up than those who smoked non-menthol cigarettes. Whereas this is in contrast to a prior research finding that adults who smoke menthol cigarettes were less likely to quit smoking, the prior study also found that ENDS use was associated with smoking cessation and more strongly for those who smoked menthol cigarettes¹⁵. Furthermore, our study adjusted for ethnic/racial minoritized status, which is associated with both menthol cigarette use and poor smoking cessation outcomes.

CONCLUSIONS

Though differences exist in the characteristics and usage patterns of those who regularly use Juul and Alto ENDS products, this prospective cohort study found very limited differences in smoking abstinence after one year among those who had currently or recently smoked cigarettes at baseline and regularly used either Juul or Alto. Relapse to smoking may be less likely with Juul than with Alto, which warrants further study.