Teens and young adults who use Juul brand e-cigarettes are failing to recognize the product's addictive potential, despite using it more often than their peers who smoke conventional cigarettes, according to a new study by researchers at the Stanford University School of Medicine. The findings, from an ongoing Stanford project addressing the use and perceptions of tobacco products by California youth is published in the journal JAMA Network Open.

More nicotine

Juul e-cigarettes first went on sale in 2015 and now account for two-thirds of the U.S. e-cigarette market. They deliver more nicotine than competing brands of e-cigarettes, and produce a throat hit that is more comparable to conventional cigarettes than their predecessors.

Juul's design, using flavored nicotine-containing liquids inhaled from colorful pods that resemble USB flash drives, also appeal to the youth market. The Food and Drug Administration recently launched a campaign to warn youths of the dangers of e-cigarettes and attempt to stop Juul sales to young people. However, little scientific research has been done on the impact of Juul use on teenagers and young adults.

The Stanford researchers decided to ask about Juul as part of a tobacco-use study they have been conducting in 10 California high schools. In the first phase of the study, completed in 2014 and 2015, more than 700 students in ninth or 12th grade answered questions about their use and perceptions of tobacco products. The new findings come from follow-up questionnaires completed by 445 participants from this study. They were in 12th grade or a few years out of high school when the new data were collected.

About half of the participants had heard of Juul, and 15.6 percent had used the brand. Other e-cigarettes were used by 30.4% of participants, while conventional cigarettes were smoked by 24.3% of participants. About two-thirds of the participants who used these products used more than one type of product: some combination of Juul, other e-cigarettes and conventional cigarettes.

Believed to be less harmful

The study's results emphasize the need for clear public-health messages about the risks of new types of e-cigarettes, including Juul, the researchers said. "The absence of clear messaging is interpreted as safety among adolescents," McKelvey said. Nicotine-containing products are particularly risky for teens, she added. "The earlier you're exposed to nicotine, the higher the likelihood that you'll be addicted throughout your life."

Teachers and parents also need better information, Halpern-Felsher said. "We need to get in front of identifying and explaining new and different nicotine-containing products so that we can regulate them and protect youth from using them," she said. "It took quite a while for teachers to start realizing that this product [Juul] existed and that what they were seeing in classrooms were not USBs."