A majority of popular disposable e-cigarettes tested by Duke researchers contain a potent, unregulated artificial sweetener that may enhance the appeal to young and first-time users.

The additive neotame is up to 13,000 times sweeter than table sugar and is often used in e-cigarettes that also feature fruity, candy, and cool mint flavours. Clinical studies have found that candy flavours and sweeteners increase the appeal, preference, and abuse potential of e-cigarettes and other tobacco products.

“The addition of a potent sweetener may increase the potential for addiction by facilitating initiation and chronic use,” said Eric-Sven Jordt, Ph.D., associate professor in the departments of Anesthesiology and Pharmacology and Cancer Biology at Duke and senior author of a study appearing June 2 in JAMA.

“The presence of neotame also raises toxicity concerns,” Jordt said. “While approved by the US Food and Drug Administration for use in food, it is not known whether it is safe to inhale neotame heated and vaporised by an e-cigarette.”

Jordt and colleagues—including co-lead authors Hanno C. Erythropel, Ph.D., an analytical chemist at Yale School of Medicine, and Sairam V. Jabba, Ph.D., senior research scientist in Duke’s Department of Anesthesiology—analyzed 55 disposable e-cigarettes marketed in 2024, including the popular brands Elfbar, Geekbar, Mr. FOG, and Breeze, and products that contained no nicotine or a nicotine-mimicking substance called 6-methylnicotine.

Of the 55 disposable e-cigarettes tested, all contained neotame, with an average neotame content nearly five times higher than in a Mentos mint candy. Disposable e-cigarettes containing the nicotine analogue 6-methylnicotine had even higher neotame content.

“Our study demonstrates that the artificial sweetener neotame is a ubiquitous ingredient in popular disposable e-cigarettes sold in the United States,” Jabba said. “Interestingly, less popular FDA-authorised ENDS products such as Vuse or those awaiting an authorisation decision that were introduced before 2021, such as Juul, do not contain this additive. The addition of neotame to disposable cigarettes may give these products a competitive edge. Youth and young adults strongly favour sweetened products, especially in combination with candy flavours.”

As of now, neither federal nor state regulations address the increasing presence of artificial sweeteners in tobacco products.

“FDA and state regulators need to rein in the spread of heavily sweetened, disposable e-cigarettes that have not been authorised for marketing by the FDA but are nevertheless available in local stores and from online vendors,” Jordt said. “Otherwise, gains made in the reduction of e-cigarette use by youth may be reversed.”