Perceived Credibility and Information-Verification Behavior in Relation to Self-Medication Influenced by Health Information on Social Media: A Cross-Sectional Study

Background/Objectives: Social media has become a major source of health information worldwide; however, how users appraise the credibility of online health information and verify its reliability may be associated with medication-related decision-making. This study examined the associations of perceived credibility of health information encountered on social media and information-verification behavior with self-medication among adult social media users. As a secondary exploratory objective, we examined self-reported negative perceived effects following health-related decisions influenced by social media information. Methods: A cross-sectional online survey was conducted between August 2025 and February 2026 among 1935 adult social media users. Data were collected using a structured questionnaire assessing sociodemographic characteristics, perceived credibility, information-verification behavior, health-related decisions influenced by social media, and reported perceived effects. Descriptive and bivariate analyses and multivariable logistic regression models were performed, with penalized logistic regression used as a sensitivity analysis. Results: Healthcare professionals (59.9%) and the citation of reliable sources (44.1%) were the characteristics most frequently associated with perceived credibility. Although participants generally reported moderate perceived credibility of health information encountered on social media, 54.9% reported inconsistent information-verification practices. High perceived credibility was associated with higher odds of inconsistent information-verification behavior compared with low or moderate perceived credibility (OR = 2.77; 95% CI: 2.26–3.38; p < 0.001). Self-medication influenced by social media information was reported by 32.2% of participants. After multivariable adjustment, inconsistent information-verification behavior showed the strongest association with self-medication (aOR = 14.80; 95% CI: 10.07–21.73; p < 0.001). Participants reporting low or moderate perceived credibility had lower odds of self-medication than those reporting high perceived credibility (aOR = 0.36; 95% CI: 0.26–0.49; p < 0.001). Secondary exploratory analyses restricted to participants reporting a social media-influenced health decision (n = 1556) also identified associations between reported negative perceived effects, self-medication, and information-verification behavior. These findings should be interpreted cautiously because of the retrospective self-report and sequential structure of the questionnaire items. Conclusions: Overall, perceived credibility and information-verification behavior emerged as related, but distinct dimensions of digital health-information appraisal associated with medication-related decision-making. These findings highlight the importance of digital health literacy strategies that promote critical appraisal and systematic verification of online health information before it is incorporated into medication-related decisions.