Purpose: Transition from female to male gender after initiation of hormonal therapy involves both phenotypic and physiological changes. The response to treatment can vary widely from person to person. In this study, we looked at the response of the menstrual cycle after the initiation of testosterone therapy and we wished to determine the time period and dose of testosterone leading to the cessation of menses in transgender men. Methods: A retrospective chart review of 114 transgender men (individuals assigned female gender at birth but later identify themselves as males) seen for hormonal therapy in our transgender clinic from 2006 through 2016. Results: Forty patients were excluded from the study as they were either not menstruating (19), started therapy elsewhere (13), had incomplete data (6), or were treated with transdermal testosterone (2). Of the 74 patients begun on low dose (20-40 mg weekly) intramuscular testosterone, 55% had cessation of menses within 6 months, 32% took more than 6 to 12 months, and 7% had not had complete cessation by 1 year and were prescribed progesterone (5% were given progesterone after menses had not ceased by 4 months for personal preference). The dose of testosterone correlated only loosely with the time of cessation (mean dose 40.1±8.1 mg/week for those <6 months and 56.1±12.0 mg/week for those who took 6-12 months). Conclusion: The initiation of low to moderate testosterone was sufficient in leading to menstrual cessation in the majority of patients by 6 months and nearly all by 1 year. There was individual variability in the time to cessation with little correlation to testosterone dose.
Keywords: female to male transgender; menstrual cycles; testosterone.