Early body composition changes in trans women on low-dose estradiol: comparing oral vs sublingual administration using dual energy absorptiometry and bioelectrical impedance analysis.

Background: Low-dose sublingual estradiol gender-affirming hormone therapy (GAHT) in treatment-naive transgender women effectively suppresses testosterone and initiates breast development, comparable to oral estradiol with cyproterone acetate; however, its impact on body composition remains unstudied.

Aim: To assess early body composition changes with low-dose estradiol, compare sublingual versus oral administration efficacy, and evaluate bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) agreement in transgender women undergoing GAHT.

Methods: In this 6-month prospective study, 22 treatment-naïve transgender women received either 2 mg/day sublingual estradiol (SLE) or combined oral (CO)-2 mg/day oral estradiol plus 10 mg/day cyproterone acetate.