A prospective comparison study of subcutaneous and intramuscular testosterone injections in transgender male adolescents.
Level 3 - non-randomized controlled study
Prospective comparative study with mixed randomization and patient preference allocation
PubMed 37788646 · doi:10.1515/jpem-2023-0237
What was done
Prospective comparative study evaluating subcutaneous (SQ) versus intramuscular (IM) testosterone injections over 6 months in testosterone-naïve transgender and gender diverse adolescents assigned female at birth (ages 14–18 years). Participants were either randomized to an injection route or selected their preferred modality. Assessments at baseline, 3 months, and 6 months included peak and trough testosterone levels, PedsQL quality of life scores, self-reported masculinization, adverse events, and injection experience questionnaires.
What was found
Twenty-six subjects completed the study (median age 15.5 years). By 6 months, trough testosterone levels were comparable between SQ and IM groups. Peak testosterone levels were higher in the IM group at 3-month follow-up. Mild adverse effects were rare (12%, all in SQ subjects) and limited to skin reactions. Self-reported masculinization effects and quality of life scores were not statistically different between injection groups. By 3 months, 92% of participants were self-injecting. Exact numerical values for hormone concentrations and quality of life scores were not reported in the abstract.
Why it matters
Demonstrates that subcutaneous testosterone provides similar short-term trough levels and clinical outcomes to traditional intramuscular injections, supporting subcutaneous self-administration as a viable option in adolescent gender-affirming care.
Limits
The sample size is very small (n=26). Allocation allowed participant preference alongside randomization, introducing potential selection bias and confounding. Follow-up was limited to 6 months, precluding evaluation of long-term masculinization or safety profiles.
Cited by
- supports Subcutaneous injection of testosterone provides slower absorption and more stable serum hormone concentrations compared to intramuscular injection.