Transgender hormone therapy (female-to-male) to individuals taking bioidentical hormones in the form of testosterone (including esters) and do not apply to those taking synthetic AAS (e.g., nandrolone) or dihydrotestosterone. Transgender hormone therapy (female-to-male) Transgender hormone therapy of the female-to-male (FTM) type, also known as masculinizing hormone therapy, is a form of hormone therapy and sex reassignment therapy which is used to change the secondary sexual characteristics of transgender people from feminine (or androgynous) to masculine. It is one of two types of transgender hormone therapy (the other being male-to-female), and is predominantly used to treat transgender men and other transmasculine individuals. Some intersex people
Transgender hormone therapy (male-to-female) suggesting a protective role of the male sex-determination chromosome. On the other hand, men with Klinefelter's syndrome (two X chromosomes and one Y chromosome), which causes hypoandrogenism, hyperestrogenism, and a very high incidence of gynecomastia (80%), have a dramatically (20- to 58-fold) increased risk of breast cancer compared to men with one X chromosome, closer to the rate of homogametic females. The incidences of breast cancer in karyotypical men (46,XY karyotype), men with Klinefelter's syndrome (47,XXY karyotype), and karyotypical women (46,XX karyotype) are approximately 0.1%, 3%, and 12.5%, respectively. Individuals with the 46,XY karyotype affected by complete androgen insensitivity syndrome