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Wolfson Institute of Preventive Medicine - Barts and The London

European version of most popular US e-cigarette may have “limited potential” to help UK smokers quit

A study by Wolfson Institute researchers shows that the European version of the US Juul e-cigarette delivers much less nicotine than Juul US. Juul US is currently the most popular e-cigarette  in the United States, and is expected to be particularly effective in helping smokers quit, because it uses protonated nicotine to deliver nicotine in a similar way to cigarettes. Results from the new study show that this innovative feature does not compensate for the lower nicotine content in the EU version of the product, and the EU version may therefore have more limited treatment potential to help smokers quit. In the UK, where EU Tobacco Products regulations apply, nicotine concentrations of over 20 mg/ml in e-liquid are prohibited.

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The within-subjects crossover design study compared the pharmacokinetic profile and user ratings of Juul EU (20mg/ml nicotine), Juul US (59 mg/ml nicotine), cigarettes and other e-cigarette products. In a series of testing sessions intravenous blood sampling lines were placed in participants’ arms, and baseline samples of up to 5 ml were taken. Participants then smoked/vaped (depending on which product was being tested) as much or as little as they wanted for five minutes, the time it usually takes to smoke a cigarette. Further samples of up to 5 ml each were then taken at 2, 4, 6, 8, 10 and 30 min after product initiation. Results showed that Juul EU delivered less nicotine and was perceived to relieve urges to smoke less than Juul US.

Professor of Clinical Psychology, Peter Hajek, an author on the paper and the Director of the Health and Lifestyle Research Unit at the Wolfson Institute, said:  “Smokers in the UK and in the rest of the EU are only allowed to use a product that is unlikely to be helpful. The limited nicotine content in the EU version of the product raises questions about the rationale and impact of the EU Tobacco Products Directive.”  

Nicotine delivery and user reactions to Juul EU (20 mg/ml) compared with Juul US (59 mg/ml), cigarettes and other e-cigarette products Anna Phillips-Waller, Dunja Przulj, Katie Myers Smith, Francesca Pesola, Peter Hajek.  (Psychopharmacology, 2020)