The nationwide Danish healthcare service for children and adolescents with gender dysphoria opened in 2016, based on clinical experience from other European countries and early follow-up studies, implying that early medical transition resulted in better physical and psychological outcomes. This review discusses how a rapid increase of referrals, especially among adolescent birth-assigned girls, and other factors such as high rates of psychiatric morbidity and varying developmental trajectories of gender identity have affected international and Danish healthcare in recent years.