Long-term gender-affirming hormone therapy (GAHT) for transgender men is safe and effective. Low-dose testosterone administration is sufficient to increase lean body mass (LBM) in transgender men. And higher testosterone doses can lead to an earlier increase in muscle mass.
These are the findings of a study – “Trans men can achieve adequate muscular development through low-dose testosterone therapy: A long-term study on body composition changes” by Yusuke Tominaga, Tomoko Kobayashi, Yuko Matsumoto, et al – that appeared in Andrology.
Transgender individuals often face unique challenges in aligning their physical bodies with their true gender identity. Among the various methods employed, GAHT stands as a vital means for transgender men to achieve physical changes in consonance with their gender identity. Navigating the complexities that come with gender transition, transgender individuals seek medical interventions to alleviate gender dysphoria and align their bodies with their gender identity.
According to the researchers, for transgender men, testosterone therapy holds promise in inducing masculinizing effects such as increased muscle mass, cessation of menstruation, and deepening of the voice. However, the lack of comprehensive research on the long-term effects and safety of testosterone therapy poses significant challenges in clinical decision-making and underscores the persistent taboo surrounding transgender healthcare.
For this study, the researchers analyzed data from transgender men who commenced GAHT between May 2000 and December 2021, recording physical findings, blood test results, and menstrual cessation rates. They then compared the effects of testosterone on body composition changes and laboratory parameters, stratifying participants into low-dose and high-dose groups based on their testosterone dosage.
The findings of the study revealed that both low-dose and high-dose testosterone regimens demonstrated favorable outcomes, with no significant differences observed in menstrual cessation rates up to 12 months.
Over time, participants exhibited a decrease in body fat percentage and an increase in lean body mass, indicative of the desired masculinizing effects of testosterone therapy.
Notably, the high-dose group exhibited greater gains in lean body mass during the initial year of therapy, suggesting a potential strategy for individuals seeking more rapid changes in body composition.
Importantly, the study found no evidence of long-term, dose-dependent side effects such as polycythemia or dyslipidemia, reassuring both clinicians and transgender individuals regarding the safety profile of testosterone therapy.
Reflecting on the significance of their findings, Tominaga explained: “By elucidating the safety and efficacy of hormone therapy, we hope to alleviate uncertainties surrounding transgender healthcare and empower individuals to make informed decisions about their treatment.”
