A Randomized Controlled Trial Comparing Testosterone Enanthate and Testosterone Undecanoate as a Gender Affirming...

Area of Science:

• Endocrinology
• Transgender Health
• Pharmacology

Background:

• Testosterone is the sole gender-affirming hormonal therapy (GAHT) for female-to-male (FtM) individuals, aiming to reduce gender dysphoria and induce masculinization.
• Understanding the comparative effects of different testosterone formulations is crucial for optimizing treatment outcomes.

Purpose of the Study:

• To investigate the clinical, biochemical, and hormonal effects of two testosterone formulations: testosterone enanthate (TE) and testosterone undecanoate (TU).
• To compare the efficacy and safety of TE versus TU as GAHT in transgender men.

Main Methods:

• A prospective randomized controlled trial over 28 months involving 58 testosterone-naive transgender men.
• Participants were randomized to receive either TE (n=29) or TU (n=29).
• Assessment of clinical (e.g., menstrual cessation, hair growth, voice deepening) and biochemical parameters (hematological, lipid, hormonal profiles) at baseline, 6 months, and 1 year.

Main Results:

• Both TE and TU groups achieved desired masculinizing effects within one year.
• Statistically significant increases in hemoglobin, hematocrit, LDL cholesterol, and testosterone levels were observed in both groups.
• Significant decreases in HDL cholesterol and estradiol levels were noted, with no significant differences between the TE and TU groups despite fewer injections for TU.

Conclusions:

• Both testosterone enanthate (TE) and testosterone undecanoate (TU) are safe, effective, and well-tolerated GAHT options for transgender men.
• No significant differences in clinical, biochemical, or hormonal parameters were found between the two formulations.
• Testosterone undecanoate (TU) was preferred due to its less frequent dosing interval, enhancing patient adherence and convenience.