A Randomized Controlled Trial Comparing Testosterone Enanthate and Testosterone Undecanoate as a Gender Affirming Hormonal Therapy in Trans Males.

Objective: Testosterone is the only available gender affirming hormonal therapy (GAHT) for female-to-male (FtM) transsexuals, to alleviate gender dysphoria and to obtain desired masculinizing effects. The objective is to study the effect of two different formulations of testosterone- testosterone enanthate (TE) and testosterone undecanoate (TU) on various clinical, biochemical and hormonal parameters.

Design: This is a prospective randomized controlled trial conducted over a period of 28 months in a Transgender multi-specialty clinic. Fifty-eight testosterone naive transgender men, randomized into two groups, 29 received TE and the remaining 29 received TU.

Patients and measurements: The variables assessed were cessation of menstrual cycles, onset of facial and body hair, deepening of voice, waist-to-hip ratio, clitoromegaly, muscle strength, hematological, lipid, liver functions and gonadal hormonal profile. The changes were compared at baseline, 6 months and 1 year following TE and TU and compared between the groups.

Results: Both groups had desired masculinizing effects at the end of 1 year. There was a statistically significant increase in hemoglobin, hematocrit, LDL cholesterol and testosterone levels with a simultaneous decrease in HDL and estradiol levels at 1 year in both the groups with no statistical significance between the groups, despite the lesser number of injections received by TU group than TE group (6 vs. 18).

Conclusion: Both TE and TU is safe, effective and well tolerated GAHT among FtM transsexuals with no significant differences in clinical, biochemical and hormonal parameters. Testosterone undecanoate was preferred at the end of 1 year due to its long dosing intervals.