Hormone Concentrations in Transgender Women Who Self-Prescribe Gender Affirming Hormone Therapy: A Retrospective Study

Abstract

Self-prescribed gender-affirming hormone therapy (GAHT) is common practice among transgender women, especially in resource-limited countries, yet the effectiveness of each GAHT regimen to achieve female range sex hormone concentrations is not known. To describe the use and sex hormone concentrations of various GAHT regimens among transgender women who self prescribe in Thailand. This was a retrospective study in a community-based setting. Five hundred and 27 records of transgender women taking GAHT who were receiving care at a community health center between January 1, 2018, and December 31, 2020 were included for the analysis. Blood total testosterone and estradiol concentration after at least a 6-month period of GAHT. Multiple GAHT regimens were identified including oral estradiol valerate (EV), transdermal 17β-estradiol gel, injectable EV with hydroxyprogesterone caproate, injectable estradiol benzoate with progesterone, oral EV with cyproterone acetate (CPA), and oral contraceptive pills (OCPs). The most common GAHT regimen used by 49.1% of the participants was OCPs that contained 0.035 mg of ethinyl estradiol and 2 mg of CPA. Only 25.2% of this group had female range testosterone concentrations (<50 ng/dL). Oral EV and CPA were used by 23.1% of the participants. Most of them used 12.5 mg of CPA and 47.7% of this group had female range testosterone concentrations. There was no statistical significance between mean testosterone concentrations in CPA 12.5 and 25 mg groups, (P = .086). The inadequate sex hormone levels found in these commonly self-prescribed GAHT regimens provide information regarding the efficacy and safety of GAHT regimens for health care providers working with transgender women in a community-based setting. This study reflected a real-world situation and provided hormonal profiles among transgender women taking self-prescribed GAHT. However, issues in recall, medical literacy, and adherence to the medication may limit the results. Combined hormonal contraceptive pill was a commonly used GAHT regimen in Thai transgender women who self prescribe GAHT. However, this regimen was not effective to decrease testosterone concentrations to the recommended range of less than 50 ng/dL. Overall, self-prescription of GAHT does not appear to be effective in reaching target sex hormone concentrations. Including health care providers in the prescription and monitoring of GAHT may be a more effective approach in the delivery of GAHT.