Researchers from University of California San Diego Herbert Wertheim School of Public Health and Human Longevity Science have found that high-nicotine e-cigarette use rose sharply among young adults between 2017 and 2022 and was associated with increased nicotine dependence and more persistent vaping. The study, published on Oct. 20, 2026 in the Tobacco Control journal, found that by 2022, nearly half (49.2%) of young adults who vaped daily were using e-cigarettes containing at least 4% nicotine – considered a high-nicotine product. Among daily vapers ages 55 and older, just 4.5% were using products with that level of nicotine. Overall, among people who vaped in 2022, the odds of using a high-nicotine e-cigarette were 12 times higher for 18- to 24-year-olds than for adults ages 55 and older.
"The Food and Drug Administration's (FDA) authorization of these products was based in part on the expectation that the benefits to adults who smoke would outweigh the risks of creating new nicotine dependence among young people," said John P. Pierce, PhD, senior author and professor at the Herbert Wertheim School of Public Health. "Our findings suggest that this balance needs to be reassessed. Young adults are disproportionately choosing high-nicotine products, including within the same brands used by older adults, and that use is associated with substantially greater nicotine dependence."
The researchers analyzed data from the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative study that follows tobacco and nicotine use in the U.S. The analysis included surveys conducted in 2017, 2019, 2021 and 2022, as well as longitudinal data from 2,356 adults who vaped in 2019 and whose behaviors were tracked through 2022.
In 2017, fewer than 4% of people who vaped reported using an e-cigarette with at least 4% nicotine. Among 18- to 24-year-olds who vaped daily, that figure rose from 3.1% in 2017 to 40.1% in 2019 and 49.2% in 2022. By comparison, 32.8% of daily vapers ages 25 to 34, 17.6% of those ages 35 to 54 and 4.5% of those 55 and older used high-nicotine products in 2022.
The rise in high-nicotine vaping coincided with a substantial increase in nicotine dependence among young adults who exclusively vaped. In 2017, 18- to 24-year-olds who exclusively vaped had substantially lower nicotine dependence scores than those who exclusively smoked cigarettes. By 2022, their dependence scores had risen to a level equivalent to that of 18- to 24-year-olds who exclusively smoked in 2017.
The study also found that nicotine strength was associated with dependence across age groups. People who used high-nicotine e-cigarettes showed higher levels of nicotine dependence than those who used lower-nicotine products. Among people who vaped in 2019, those using high-nicotine e-cigarettes had 31% lower odds of being abstinent from vaping four years later. Overall, 40.9% of those who vaped in 2019 – including those who did not vape daily – were abstinent by 2022.
The researchers say the strong age difference in nicotine strength used raises questions about the role of marketing. Among people who used the same brands, 18- to 24-year-olds were more likely than adults ages 25 and older to choose high-nicotine versions. Two brands with particularly large differences have been marketed through paid social media influencers, although the study was not designed to establish that marketing caused young adults to choose higher-nicotine products.
The authors note that the study cannot establish that high-nicotine e-cigarettes directly caused the increase in nicotine dependence because it was observational rather than a randomized clinical trial. The researchers also note that many participants, particularly in the first two years, did not know the nicotine strength of their e-cigarette, which would tend to make the study's estimates more conservative.
The findings also raise questions about whether high-nicotine e-cigarettes continue to meet the public health standard required for FDA marketing authorization. The researchers argue that the evidence warrants an urgent reassessment of whether the benefits of these products for adults who smoke continue to outweigh the risk of creating nicotine dependence among people who do not smoke.
"We need to understand not only who is using these products, but how the nicotine content, product design and marketing environment are influencing long-term patterns of use," said Pierce. "Previous research has questioned the effectiveness of e-cigarettes in helping smokers quit. In this study, we have documented that high-nicotine products have created a new generation of people who are dependent on nicotine."
Read the full study: " High-nicotime e-cigarettes and nicotine dependence among US young and older adults, 2017-2022. "
Additional co-authors on the study include: David Strong, PhD, Matthew Stone, PhD, Natalie Quach, Jiayu Chen, Dennis Trinidad, PhD, Sara McMenamin, PhD, Yuyan Shi, PhD, and Karen Messer, PhD, from UC San Diego. Brian Dang from UC San Francisco. Siyuan Ping from Indiana University.
The study was funded, in part, by the Tobacco-Related Disease Research Program of the University of California, Office of the President (T31IR-1584 and T32IR-4988).
Authors declare no competing interests.
