AbstractThe rapidly changing U.S. e-cigarette marketplace is dominated by unauthorized products. We used retail scanner data from Circana, a market research company that collects point-of-sale scanner data from a large retail sample, to estimate the proportion of unauthorized e-cigarette product sales in U.S. brick-and-mortar stores. As of December 2025, 69.4% of e-cigarette product sales in convenience and grocery channels were estimated to be unauthorized. Most unauthorized products were disposable devices in flavors that may appeal to young people. More complete data on products and sales in untracked channels such as vape shops could better inform monitoring and enforcement efforts.