Introduction People believe that cigarettes using ‘organic,’ ‘additive-free’ or similar descriptors are less harmful than other cigarettes. Natural American Spirit (NAS) is the most popular US cigarette brand using these descriptors. This cohort study describes changes in US smokers’ odds of preferring NAS and changes in NAS smokers’ odds of believing their brand might be less harmful than other brands.

Methods Data come from four waves (2013–2018) of the Population Assessment of Tobacco and Health (PATH) Study. Generalised estimating equations produced population-averaged estimates of relationships between (1) NAS brand preference and wave and (2) belief that one’s own brand might be less harmful than other brands, wave and NAS brand preference. Models tested interactions by age group and sexual minority status.

Results The odds that smokers preferred NAS increased by 60% in W4 relative to W1. Disproportionate preference by younger adult and sexual minority smokers was observed. The odds that NAS smokers believed their own brand might be less harmful decreased by 50% between W1 and W4, but this perception was still 16 times higher for NAS compared with non-NAS smokers. Given the increasing preference for NAS, there was no significant change in the absolute number of NAS smokers who believed their own brand might be less harmful (W1: 562 122 (95% CI 435 190 to 689 055) vs W4: 580 378 (95% CI 441 069 to 719 689)).

Conclusions Both brand popularity and concentration of brand-related harm perceptions are important for understanding population impact of changes in cigarette marketing.