Dose-response analysis of testosterone replacement therapy in patients with female to male gender identity disorder

Aya Nakamura, Masami Watanabe, Morito Sugimoto, Tomoko Sako, Sabina Mahmood, Haruki Kaku, Yasutomo Nasu, Kazushi Ishii, Atsushi Nagai, Hiromi Kumon

Research output: Contribution to journalArticlepeer-review

73 Citations (Scopus)


Gender identity disorder (GID) is a conflict between a person's actual physical gender and the one they identify him or herself with. Testosterone is the key agent in the medical treatment of female to male GID patients. We conducted a dose-response analysis of testosterone replacement therapy (TRT) in 138 patients to determine the onset of the therapeutic effects. The TRT consisted of intramuscular injection of testosterone enanthate and patients were divided into three groups; 250 mg every two weeks, 250 mg every three weeks and 125 mg every two weeks. The onset of deepening of voice, increase in facial hair and cessation of menses was evaluated in each group. At one month after the start of TRT, the onset of these physical changes was more prevalent in the group receiving the higher dose of testosterone, and there were dosedependent effects observed between the three treatment groups. On the other hand, at six months after the start of TRT, most of the patients had achieved treatment responses and there were no dose-dependent effects with regard to the percentage of patients with therapeutic effects. No significant side effects were observed in any of the treatment groups. We demonstrated that the early onset of the treatment effects of TRT is dose-dependent, but within six months of starting TRT, all three doses were highly effective. Current study provides useful information to determine the initial dose of TRT and to suggest possible changes that should be made in the continuous dosage for long term TRT.

Original languageEnglish
Pages (from-to)275-281
Number of pages7
JournalEndocrine journal
Issue number3
Publication statusPublished - 2013


  • Dose response analysis
  • Estradiol
  • Female to male
  • Gender identity disorder
  • Testosterone

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology


Dive into the research topics of 'Dose-response analysis of testosterone replacement therapy in patients with female to male gender identity disorder'. Together they form a unique fingerprint.

Cite this