This study explores how social validation affects the trustworthiness of health information on online forums by comparing the influence of expert opinions versus opinions from a large number of anonymous users. Using a 2x2 within-subjects design, the study manipulated cues of social validation (quality vs. quantity) in forum posts and assessed their impact on perceived credibility and trustworthiness. Results indicated that users valued social validation by the masses as much as expert validation. However, they did not critically evaluate the accuracy of information based on the quantity of validation from the masses.