Objective Hormone treatment is an important part of gender reassignment therapy in gender dysphoria. Previous data about efficacy and safety are commonly based on small cohorts or they comprise former cohorts under meanwhile obsolete therapy regimes. Our objective was to investigate these topics in a large cohort of individuals under guideline-based treatment. Design/methods Cohort study of medical files of n = 155 male-to-female (transwomen) and n = 233 female-to-male transgender persons (transmen) of an Endocrine outpatient clinic between 2009 and 2017. Results Median time to reach amenorrhoea in transmen under testosterone monotherapy was 3 months, regardless of whether testosterone undecanoat or gel was used. Transmen with higher levels of hemoglobin 3–4 months after onset of GAHT had a greater chance to reach amenorrhea early, whereas testosterone levels showed no significant correlation (hemoglobin: HR: 1.639; 95% CI: 1.036–2.591, P = 0.035; testosterone: HR: 0.999; 95% CI: 0.998–1.001, P = 0.490). Estradiol levels (ρ −0.117; P = 0.316) had no significant influence on breast development in transwomen. Testosterone levels (ρ −0.398; P < 0.001) and FAI (ρ 0.346; P = 0.004) were significantly negatively correlated with reached Tanner stage. Liver values and blood lipids showed an alignment to reference range of the required sex in both groups. Relevant elevations of liver values were rare (2.44% in transmen, 4.23% in transwomen) and transient in most cases. Most relevant side effects were acne (44.8%), respectively erythrocytosis (up to 5.6%) in transmen and venous thrombembolism (1.9%) in transwomen. Conclusions Gender-affirming hormone therapy in accordance with current clinical practice guidelines is efficient and safe.

Introduction The number of individuals requesting medical treatment for gender dysphoria has increased significantly within the past years. Our purpose was to examine current biographic and socio‐demographic characteristics and aspects of legal gender reassignment. Design Medical files from n = 350 individuals of a German Endocrine outpatient clinic were collected from 2009 to 2017 and analysed retrospectively. Results Ratio of transwomen to transmen equates to 1:1.89 with a remarkable increase of transmen by the year 2013, showing a reversal of gender distribution compared with previous studies for the first time. Use of illegal substances or self‐initiated hormone therapy was rare (4.6 and 2.1%). Satisfaction with gender‐affirming hormone therapy was significantly higher in transmen than in transwomen (100% vs 96.2%, P = .005). Use of antidepressants declined significantly after onset of hormone treatment in transmen (13% vs 7%; P = .007). The number of individuals with a graduation diploma was only about half as high as in the general population (14.3% vs 27.3%), whereas unemployment rate was more than twice as high (14% vs 6.9%). Median latency between application for legal gender reassignment and definitive court decision was 9 months. Conclusions Our data provide possible indications for a decline of psychosocial burden in individuals diagnosed with gender dysphoria over the last years. However, affected individuals are still limited in their occupational and financial opportunities as well as by a complex and expensive procedure of legal gender reassignment in Germany.