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Effect of flavour manipulation on ENDS (JUUL) users’ experiences, puffing behaviour and nicotine exposure among US college students
  1. Mayra Vargas-Rivera1,
  2. Mohammad Ebrahimi Kalan1,
  3. Melissa Ward-Peterson2,
  4. Olatokunbo Osibogun1,
  5. Wei Li1,
  6. David Brown3,
  7. Thomas Eissenberg4,
  8. Wasim Maziak1
  1. 1Epidemiology, Robert Stempel College of Public Health, Florida International University, Miami, Florida, USA
  2. 2Community Based Research Institute, Robert Stempel College of Public Health, Florida International University, Miami, Florida, USA
  3. 3Family and Community Medicine, Florida International University College of Medicine, Miami, Florida, USA
  4. 4Psychology and Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
  1. Correspondence to Dr Wasim Maziak, Epidemiology, Robert Stempel College of Public Health, Florida International University, Miami, FL 33199, USA; wmaziak{at}


Significance Electronic nicotine delivery system (ENDS) use has continued to increase exponentially among young people in the USA, with unique flavours being one of the most cited reasons for use. Yet, controlled studies examining the effects of restricting flavour are lacking. This study evaluates the impact of ENDS flavour manipulation on user’s puffing behaviour, subjective experience, harm perception and nicotine exposure among college-aged ENDS users.

Methods JUUL users (n=30, age 18 to 24 years) attended two 60 min ad libitum ENDS use sessions (JUUL preferred flavour vs JUUL classic tobacco flavour) in a cross-over design. Puff topography and plasma nicotine concentration were measured, and participants completed subjective experience questionnaires.

Results Increases were observed on measures of satisfaction, taste, enjoyment, urges to vape/smoke, pleasure, product appeal and increased concentration following using the preferred flavour pod (p values <0.05). Compared with preferred flavour, participants in the tobacco flavour were less motivated to use it in the future (70.9 vs 19.1 scores, p<0.001), even if it was the only product on the market (75.8 vs 30.7 scores, p<0.001). While nicotine levels significantly increased in both conditions from pre to post session (p values <0.001), no significant differences were observed in nicotine boost levels or on puff topography parameters when comparing both flavour conditions.

Conclusions This pilot study provides evidence that ENDS flavours have a substantial effect in enhancing young current ENDS users’ experiences, product appeal and motivation to use the product in the future. It highlights that limiting flavours could play a potential role when designing strategic policies to reduce the appeal of ENDS use among young people.

  • electronic nicotine delivery devices
  • nicotine
  • non-cigarette tobacco products
  • smoking topography
  • harm reduction

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  • Correction notice This paper has been updated since first published to update 'Competing interests' statement and correct first author's name to 'Mayra Vargas-Rivera'.

  • Contributors WM, MW-P and MVR contributed to the conception and design of the study, supervised data collection, contributed to interpretation of the data and critically revised the manuscript for important intellectual content. MVR, MEK and WL collected the data. MVR performed the initial analyses and drafted the initial manuscript. TE, DB, OO, MEK and WL contributed to interpretation of the data and critically revised the manuscript for important intellectual content. This manuscript was written by MVR with input from all co-authors who read and approved the final version.

  • Funding This project was funded intramurally by the Florida International University Office of Research and Economic Development (FIU-RCMI) Pilot Study Program. MV is supported by the National Institute of Health Fogarty International Center (NIH FIC) under award R01TW010654. MEK is supported by the National Institute on Drug Abuse at National Institutes of Health (NIDA NIH) under award R01DA042477. MW-P is currently supported by the National Institute of Minority Health and Health Disparities under award U54MD012393 for FIU-RCMI. OO is supported by the NIDA NIH under award T32DA043449. TE is supported by the NIDA NIH under award number U54DA036105 and the Center for Tobacco Products of the US Food and Drug Administration. WM is supported by the NIH FIC under award R01TW010654 and the NIDA NIH under award R01DA042477.

  • Disclaimer The content is solely the responsibility of the authors and does not necessarily represent the views of the NIH or the FDA.

  • Competing interests TE is a paid consultant in litigation against the tobacco industry and also the electronic cigarette industry and is named on a patent for a device that measures the puffing behaviour of electronic cigarette users.

  • Patient consent for publication Not required.

  • Ethics approval This study was approved by Florida International University Institutional Review Board.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request. De-identified data is available upon reasonable request to: Dr Wasim Maziak, MD, PhD, Professor and Chair, Department of Epidemiology, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, Phone: 305-348-4501, Email:

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