Public stigma characterizes three leading health issues: prescription opioid addiction, obesity, and cigarette smoking. Attributions of individual responsibility are often embedded in negative public attitudes around these issues and can be important to stigma's development and reduction. Research suggests that narrative messages may hold promise for influencing attributions and stigma in these health contexts. Using a national sample of American adults from an online panel (N = 5,007), we conducted a survey-embedded randomized experiment, assigning participants to read one of six messages about one of three health issues. All participants read a statement detailing the magnitude of their assigned health problem, after which some respondents received a short inoculation message (serving as a comparison group) or a narrative message emphasizing external factors while acknowledging personal responsibility for the issue. Some participants also read a counter message emphasizing personal responsibility for the health issue to replicate competitive messaging environments surrounding these issues. Relative to those who received only the magnitude of problem message (comparison group 1) or the magnitude of problem and inoculation messages (comparison group 2), the narrative message reduced prescription opioid addiction stigma and increased attributions of responsibility to groups beyond the individual. Narrative effects were mixed for obesity, had no effect on attributions or stigma around cigarette smoking, and were generally consistent whether or not respondents received a counter message. Narrative messages may be a promising approach for shifting responsibility attributions and reducing public stigma around prescription opioid addiction, and may have some relevance for obesity stigma-reduction efforts.