Gender identity does not always develop in line with biological sex. Gender dysphoria at young age implies a strong incongruence between gender identity and the assigned sex; the rejection of oneś sexual attributes and the desire to belong to the opposite sex; and a significant clinical suffering or impaired individual functioning in life spheres. The purpose of this chapter is a narrative review of the literature available on puberty suppression therapy through GnRH analogues. Biological puberty provides intense suffering to the adolescent with gender dysphoria who does not recognize himself in his own body. These drugs suppress the production of endogenous gametes and sex hormones. Although the effects of therapy are reversible, and biological development resumes spontaneously once the medication is stopped, the administration of GnRH analogues at a young age has fueled a scientific debate on the matter of the ethics of pharmacological intervention with minors. In conclusion, the studies considered show that GnRH analogues do not have long-term harmful effects on the body; prevent the negative psychosocial consequences associated with gender dysphoria in adolescence (suicidal ideation and attempts, self-medication, prostitution, self-harm); improve the psychological functioning of young transsexuals; and are diagnostic tools that allow adolescents to buy time to explore their gender identities.