Findings
In this study comprising 2 surveys conducted among 2469 youths (aged 11-18 years) and 12 046 adults (aged ≥18 years) from Great Britain, youths had higher odds of reporting no interest in trying e-cigarettes in standardized green packaging than e-cigarettes in branded packaging, but adults had lower odds of reporting no interest in trying e-cigarettes in standardized green packaging than e-cigarettes in branded packaging.