Governing E-cigarettes in China: regulatory challenges and strategies for adolescent protection in the post-flavor ban era.

China's e-cigarette governance has entered a complex post-flavor ban era under the "1 + 2 + N" regulatory framework. While this system integrates centralized transaction platforms and mandatory safety standards, critical vulnerabilities remain. Current regulatory asymmetry, characterized by strict e-cigarette flavor prohibitions alongside lenient policies for flavored combustible tobacco, may inadvertently redirect consumption toward traditional smoking products. Meanwhile, the expansion of covert online marketing and illicit social media networks continues to facilitate adolescent access, weakening enforcement effectiveness. Addressing these challenges requires a coordinated policy response. This article proposes extending flavor restrictions to combustible cigarettes to enhance regulatory consistency and raising the legal purchase age with reference to international "Tobacco 21" experience. It further highlights the need to strengthen algorithmic governance to curb hidden digital promotion and to apply nudge-based interventions, such as neutral packaging and graphic warnings, to reduce product appeal. Integrating these supply- and demand-side measures is essential to limit youth initiation, contain illicit market growth, and reinforce long-term public health protection.