The 2017 agreement between the U.S. Food and Drug Administration and the makers of Natural America Spirit (NAS) cigarettes restricted the use of "additive-free" (AF) in brand marketing, which the company replaced with "tobacco ingredients: tobacco & water" (TW), a phrase subsequently adopted by L&M. We tested how participants' perceptions differed when exposed to AF versus TW claims on NAS and L&M packs. A between-subjects experiment was embedded within an online survey in August 2022 (n = 2526). Participants were randomized to view one of three packs (NAS AF pack, NAS TW pack, L&M TW pack). Logistic regressions assessed differences (by pack exposure) in perceived pack attractiveness and relative chemical and harm perceptions compared to other cigarettes. Interactions by smoking status were explored. No significant differences were observed between the NAS AF and NAS TW packs on perceived attractiveness or relative harm, although never smokers had higher odds of having lower relative chemicals perceptions in response to the NAS AF versus NAS TW pack (OR = 1.81). Compared to participants who saw the NAS TW pack, those who saw the L&M TW pack tended to have lower odds of perceiving the pack as attractive, believing that the product had fewer chemicals than other products, or believing the product was less harmful than other products compared to the NAS TW pack. Results suggest the more implicit "tobacco ingredients: tobacco & water" claim functions similarly to "additive-free" and as an unauthorized modified risk claim. NAS brand image also appears to contribute to higher perceived pack attractiveness and lower perceptions of chemicals and harm. Additional marketing regulations and corrective campaigns may be needed to reduce risk-related misperceptions about NAS cigarettes. Our findings show that replacing "additive-free" claims with "tobacco ingredients: tobacco & water" did not sufficiently address the illegal use of unauthorized modified risk claims by the makers of NAS cigarettes. Further regulatory action restricting the TW claim could potentially reduce inaccurate lower harm perceptions about NAS cigarettes. Educational campaigns may also be needed to mitigate NAS's history of marketing that implies reduced harm, given that the effects of implicit reduced risk claims like TW have a greater effect on pack perceptions for NAS than L&M.