Abstract
INTRODUCTION: Most e-cigarettes contain highly addictive nicotine. This study assessed trends in nicotine strength in e-cigarettes sold in the United States during January 2017-March 2022. AIMS AND METHODS: We obtained January 2017-March 2022 national retail e-cigarette sales data from NielsenIQ. We assessed monthly average nicotine strength overall, by e-cigarette product and flavor type, and manufacturer. A Joinpoint regression model assessed the magnitude and significance of changes in nicotine strength. RESULTS: During January 2017-March 2022, monthly average nicotine strength of e-cigarette products increased from 2.5% to 4.4%, an average of 0.8% per month (p < .001). Monthly average nicotine strength of disposable e-cigarettes increased the most (average monthly percentage change [AMPC] = 1.26%, p < .001) as compared to prefilled pods (AMPC = 0.6%, p < .001) and e-liquids (AMPC = 0.5%, p = .218). Monthly average nicotine strength for all flavors of e-cigarette products increased except for mint-flavored products. Increases were greatest for beverage-flavored products (AMPC = 2.1%, p < .001), followed by menthol-flavored products (AMPC = 1.2%, p < .001). Among the top 10 e-cigarette manufacturers assessed, monthly average nicotine strength decreased for Juul Labs products from 5% to 4.7% (AMPC = -0.1%, p < .001) but increased significantly for five manufacturers' products and remained unchanged at 5%-6% for four manufacturers' products. CONCLUSIONS: Monthly average nicotine strength of e-cigarette products increased overall, for most product and flavor types, and for some manufacturers in the United States during the study period. Imposing maximum limits on nicotine strength of e-cigarettes together with other evidence-based tobacco control strategies can help reduce the use of e-cigarettes among youth and increase tobacco product cessation among adults. IMPLICATIONS: From January 2017 to March 2022, the monthly average nicotine strength of disposable e-cigarettes increased substantially and exceeded prefilled pods since May 2020. E-cigarettes with menthol flavor and youth-appealing flavors, like fruit, also had sharp increases in monthly average nicotine strength. Among the top 10 e-cigarette manufacturers, monthly average nicotine strength increased or remained unchanged at a high nicotine level for all manufacturers' products, except Juul Lab's products. Comprehensive strategies including restricting sales of all flavored e-cigarettes, restricting youth tobacco product access, and imposing maximum limits on nicotine strength may help reduce youth e-cigarette use and increase tobacco cessation.