The use of gonadotropin-releasing hormone analogs (GnRHa) to suppress puberty in adolescents with gender dysphoria is a fairly new intervention in the field of gender identity disorders or transsexualism. GnRHa are used to give adolescents time to make balanced decisions on any further treatment steps, and to obtain improved results in the physical appearance of those who opt to continue with sex reassignment. The effects of GnRHa are reversible. However, concerns have been raised about the risk of making the wrong treatment decisions, as gender identity could fluctuate during adolescence, adolescents in general might have poor decision-making abilities, and there are potential adverse effects on health and on psychological and psychosexual functioning. Proponents of puberty suppression emphasize the beneficial effects of GnRHa on the adolescents' mental health, quality of life and of having a physical appearance that makes it possible for the patients to live unobtrusively in their desired gender role. In this Review, we discuss the evidence pertaining to the debate on the effects of GnRHa treatment. From the studies that have been published thus far, it seems that the benefits outweigh the risks. However, more systematic research in this area is needed to determine the safety of this approach.