BackgroundGraphic warning labels are a tobacco control best practice that is mandated in the US for cigarettes under the 2009 Family Smoking Prevention and Tobacco Control Act. However, smokeless tobacco products are not required to carry graphic warning labels, and as of September 2014, electronic cigarettes in the US carry no warning labels and are aggressively marketed, including with “reduced harm” or “FDA Approved” messages.MethodsIn this online experiment, 483 US adult non-users of tobacco were randomized to view print advertisements for moist snuff, snus, and e-cigarettes with either warning labels (current warning label, graphic warning label) or “endorsements” (a “lower risk” label proposed by a tobacco company, an “FDA Approved” label) or control (tobacco advertisement with no label, advertisement for a non-tobacco consumer products). Main outcome measures included changes in perceived harm, positive attitudes towards, openness to using, and interest in a free sample of moist snuff, snus, and e-cigarettes.ResultsThe graphic warning label increased perceived harm of moist snuff and e-cigarettes. “Lower risk” and “FDA Approved” labels decreased perceived harm of moist snuff and snus respectively. Current warning label and graphic warning label significantly lowered positive attitudes towards e-cigarettes. In this sample of non-users of tobacco, 15% were interested in a free sample of alternative tobacco products (predominantly e-cigarettes). Proportion of participants interested in a free sample did not differ significantly across the conditions, but those interested in a free sample had significantly lower perceptions of harm of corresponding tobacco products.ConclusionsRegulatory agencies should not allow “lower risk” warning labels, which have similar effects to the “FDA Approved” label, which is prohibited, and should consider implementing graphic warning labels for smokeless tobacco products and e-cigarettes.