Sexually transmitted diseases (STDs) and especially chlamydia is a worrying problem among North-Norwegian youngsters. Gamified web applications should be valued for sexual health education, and thus STDs prevention, for their potential to get users engaged and involved with their healthcare. Aiming to achieve that youngsters become more aware of STDs we have developed "sjekkdeg.no", a gamified web application focused on sexual health targeting North-Norwegian youngsters. Gamification techniques like avatars, achievement-based gifts and social network sharing buttons have been implemented in the site that includes educational content on sexual health and a STDs symptom checker. Preliminary results show that the game-style web app could be useful to encourage users to learn more on sexual health and STDs and thus changing their risky behaviors and preventing sexually transmitted diseases.