Criteria for grading quality of medical information on isotretinoin use for acne vulgaris in the top 50 YouTube videos included in the study upon searching for "isotretinoin" and "Accutane". The content quality of videos was based on five pre-determined categories. Each category was given a rating of good (3 points), fair (2 points), poor (1 point), or not mentioned (0 points). The combined score for each video determined the overall quality of medical information (good, 10-15 points; fair, 5-9 points; poor, 0-4 points).