Comparing the Effects of Sublingual Estradiol Treatment Versus Oral Estradiol With Cyproterone Acetate (CPA) Treatment on The Coagulation System in Transgender Women: A Prospective, Controlled Cohort Study

Comparing the Effects of Sublingual Estradiol Treatment Versus Oral Estradiol With Cyproterone Acetate (CPA) Treatment on The Coagulation System in Transgender Women: A Prospective, Controlled Cohort Study

The goal of this clinical trial is to learn about the effects of different routes of estradiol administration on blood clotting in transgender women starting gender-affirming hormone therapy. The main questions it aims to answer are:

Does sublingual estradiol reduce free Protein S levels compared to oral estradiol with cyproterone acetate?

Does sublingual estradiol accelerate activation of the clotting system, as measured by thrombin generation?

Researchers will compare sublingual estradiol to oral estradiol plus cyproterone acetate to see if the way estradiol is taken changes blood clotting risk.

Participants will:

Take either sublingual estradiol (2 mg daily in divided doses) or oral estradiol (2 mg daily) with cyproterone acetate (10 mg daily) for 6 months

Provide blood samples at baseline and after 6 months to measure hormone levels and clotting factors

Attend clinic visits for monitoring, including safety checks and routine laboratory tests

Inclusion Criteria:

• Self-identified transgender women
• Aged 18 to 45 years
• Healthy individuals
• Treatment-naïve (not previously exposed to gender-affirming hormone therapy)
• Presenting for gender-affirming hormone therapy (GAHT)
• Provided written informed consent

Exclusion Criteria:

• Active smokers
• Personal or family history of venous thromboembolism (VTE) or thrombophilia
• History of malignancy in the past 5 years
• Chronic liver disease
• Chronic kidney disease
• Hyperlipidemia