Endocrine Care of Transpeople Part II

A Review of Cross-sex Hormonal Treatments, Outcomes and Adverse Effects in Transwomen

Maria Cristina Meriggiola; Giulia Gava


Clin Endocrinol. 2015;83(5):607-615. 

In This Article

Abstract and Introduction


The treatment of transwomen relies on the combined administration of anti-androgens or GnRH analogues to suppress androgen production and thereby reduce male phenotypic characteristics together with oestrogens to develop female characteristics. In transwomen, synthetic oestrogens such as ethinyl oestradiol, as well as conjugated equine oestrogens (CEE), should be avoided to minimize thromboembolic risks especially in older transwomen and in those with risk factors. Currently, available short- and long-term safety studies suggest that cross-sex hormonal therapy (CHT) can be considered safe in transwomen improving the well-being and quality of life of these individuals. Long-term monitoring should aim to decrease cardiovascular risks and should include prostate and breast cancer screenings.


Gender dysphoria (GD) is the distress that may accompany the experience of a significant incongruence between experienced/expressed gender and assigned gender. The DSM-V refers to transsexualism as to its most extreme expression with the need for medical and/or surgical intervention to suppress the phenotypic characteristics of the biological sex and to develop the desired sexual characteristics. The final purpose of medical and surgical treatment is to improve the well-being and quality of life of transpeople. The few studies available suggest that hormonal treatment is one of the important predictors for higher quality of life.[1,2]


The sex ratio of the adolescent population presenting for treatment is 1:1 for male and female genotype, which is different from the adult population.[3,4] In adults, according to DSM V, the prevalence of GD is 0·005–0·014% of adult natal males (DSM V) with a ratio up to 3:1 of genotypic male individuals to genotypic female individuals. In Japan, the number of transmen is higher than that of transwomen.[5] There is no concrete explanation for this different prevalence in Japan compared to that reported in the rest of the world and whether this represents an epidemiological bias or a biological difference remains to be determined.


Traditionally, GD has been labelled as a psychological disorder but neither neurophysiological nor psychological studies have been able to provide a satisfactory explanation for GD. Some research on the brains of transwomen reported that the sexual differentiation of the bed nucleus of the stria terminalis follows a female pattern[6] supporting a biological hypothesis for the basis of transsexualism. Another study associated longer androgen receptor gene repeat length polymorphism with male-to-female GD, but this finding remains to be confirmed.[7]