Introduction: Providing accurate information about the constituents in nicotine-containing products may help tobacco users make informed decisions about product choices. An experimental study examined a novel approach for presenting accurate constituent information about brands and types of smokeless tobacco (SLT) that could be understood by the general public. Methods: Participants were recruited through Amazon's Mechanical Turk and presented information online about 2 constituent dimensions of SLT products-nicotine and/or toxicity (for simplicity, "toxicity" in this study refers to carcinogenic constituents) Participants completed measures of knowledge and tobacco health risks at 2 time points: before and after exposure to constituent information. Results: Participants were found to increase their knowledge that toxicity contributes to disease risk and nicotine contributes to addiction, that SLT products vary in their levels of nicotine and toxicity, and that both SLT and cigarette products have higher toxicity than medicinal nicotine replacement therapies (e.g., nicotine lozenges). Study results showed no differences when presenting toxicity information alone versus presenting it in conjunction with nicotine information, and found no misperceptions or confusions about the relative harmfulness of cigarettes, SLT, or nicotine replacement therapy. Conclusions: Providing tobacco constituent information to smokers and nonsmokers will improve their knowledge about the relative toxicity across products and variations within a class of tobacco products without compromising the health risks associated with tobacco use.