Effects of testosterone treatment on transgender males: A single-institution study

Data regarding gender-affirming hormone therapy in the Asian population are sparse. We aimed to evaluate the efficacy and safety of testosterone therapy in transgender men.

A retrospective study chart review was conducted in a single university-based transgender clinic. Transgender men aged >18 years who newly started testosterone therapy during January 2015 to October 2019 were recruited. Physical changes, laboratory results, and adverse events, including cancer, thromboembolism, cardiovascular events, and death after masculinizing hormone therapy, were evaluated.

A total of 39 transgender men (mean age: 27.8 ± 6.0 years) were included. All individuals were treated with intramuscular testosterone injection with a mean follow-up of 25.2 ± 12.9 months. The most common maintenance regimen was testosterone enanthate 250 mg every 4 weeks. Masculinizing effects developed in all transgender men. There were no changes in body weight, and systolic and diastolic blood pressure. Hematocrit levels were 12% significantly increased from 39.9 ± 3.3% to 48.9 ± 2% (p < 0.001). Ten individuals (25.6%) had hematocrit >50%. Significant changes were found in decreased fasting plasma glucose, increased creatinine, and increased uric acid levels. A non-significantly increased alanine aminotransferase, increased low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol were observed. No thromboembolism, cancer, stroke, or coronary artery disease occurred.

Gender-affirming hormone therapy is an effective and safe short-term treatment in Thai transgender men. Apart from the standard recommendation, uric acid, plasma glucose, and creatinine level evaluation before and during masculinizing hormone therapy are rational practices. An intramuscular testosterone enanthate 250 mg every 4 weeks is an alternative masculinizing regimen with decent efficacy and safety profile.