Gender affirming hormonal therapy leads to body fat redistribution after twelve months of hormone therapy with significant alterations in muscle mass and strength among both transmen and transwomen.
Key Findings
Results
Transwomen experienced significant increases in subcutaneous and visceral fat following 12 months of gender-affirming hormone therapy.
Total subcutaneous fat increased by 9.2% in transwomen
Visceral fat increased by 11.3% in transwomen
P<0.001 in both cis mode and trans mode comparisons for fat increases
Study included 32 transfemale participants
Body composition was assessed using bioelectrical impedance analysis
Results
Transwomen experienced a significant decrease in muscle mass and muscle strength at all measured sites following 12 months of hormone therapy.
Muscle mass decreased by 7.7% in transwomen
P=0.033 in cis mode comparison and P<0.001 in trans mode comparison for muscle mass decrease
Muscle strength decreased at all sites with P<0.001
Study included 32 transfemale participants assessed at baseline and 12 months
Results
Transmen experienced a significant decrease in total subcutaneous fat following 12 months of gender-affirming hormone therapy.
Total subcutaneous fat decreased by 5.9% in transmen
P<0.001 for both cis mode and trans mode comparisons
Study included 22 transmale participants
Measurements taken at baseline and at 12 months following gender-affirming hormone therapy
Results
Transmen experienced a significant increase in muscle mass and muscle strength following 12 months of hormone therapy.
Muscle mass increased by 7.2% in transmen
P<0.001 for trans mode comparison only for muscle mass
Muscle strength increased at all sites except shoulder abduction on the right side (P<0.001)
Study included 22 transmale participants
Results
Serum irisin levels did not change significantly following gender-affirming hormone therapy in either transwomen or transmen.
No significant changes were observed in irisin levels following hormonal therapy
Irisin is described as an adipomyokine produced through muscle contraction
Irisin did not correlate with muscle mass or fat mass on follow up
Irisin levels were measured at baseline and at 12 months in both transfemale (n=32) and transmale (n=22) participants
Kolla B, Kalra P. (2025). Body composition following gender affirming hormone therapy in transgender individuals.. The Indian journal of medical research. https://doi.org/10.25259/IJMR_560_2025