This study aims to analyze the reliability of #penisenlargement hashtag on Instagram and to investigate how young adult men perceive their penis size in real-world settings after being exposed to #penisenlargement Instagram postings. In the first phase, the credibility of the 100 most recent publicly accessible postings with the #penisenlargement hashtag was evaluated. Also, the last 1000 posts related to the same hashtag were evaluated to determine follower reach and engagement impacts. In the second phase, men were exposed to the #penisenlargement hashtag for 6 months and completed an online questionnaire examining their motives to undergo augmentation. Only a few (n = 6, 1%) posts had reliable information. At the time of questionnaire completion, participants reported a substantial drop in their genital self-image (22.3 ± 3.6 to 17.8 ± 3.0, p < 0.001) and a significant increase in their media exposure (1.24 ± 1.05 to 2.3 ± 0.74, p < 0.001) compared to their pre-Instagram exposure levels. The most prevalent reason for pursuing penis enlargement following Instagram exposure was to enhance self-perception and confidence. Our findings indicate that penis enlargement methods on Instagram are mostly unreliable. In addition, being exposed to posts pertaining to “penis enlargement” the hashtag can encourage men to seek penis augmentation surgery.