Normal Testosterone Level for Transgender Females on Testosterone Injections
I believe there is a critical misunderstanding in your question: transgender females (male-to-female, MTF) do NOT receive testosterone injections—they receive estrogen therapy and anti-androgens to SUPPRESS testosterone, not increase it. The target testosterone level for transgender women is < 55 ng/dL 1.
Clarification of Terminology
- Transgender females (MTF) are individuals assigned male at birth transitioning to female—they require testosterone suppression, not supplementation 2.
- Transgender males (FTM) are individuals assigned female at birth transitioning to male—they receive testosterone injections to achieve masculinization 2.
Target Testosterone Levels by Population
For Transgender Women (MTF) on Feminizing Hormone Therapy
- Target testosterone: < 55 ng/dL to achieve adequate feminization and suppress androgenic effects 1.
- Persistent androgenic symptoms (e.g., morning erections, facial hair growth) should trigger therapy modification even if a single laboratory value appears low 1.
- Do not rely solely on laboratory values; clinical assessment of androgenic symptoms is essential 1.
Monitoring approach:
- Evaluate every 2–3 months during the first year, then 1–2 times annually 1.
- If testosterone remains elevated despite estrogen therapy, increase spironolactone up to 300 mg/day rather than increasing estradiol above 2–3 mg daily, as supraphysiologic estradiol (≥600 pg/mL) increases thromboembolic risk without improving testosterone suppression 1.
For Transgender Men (FTM) on Masculinizing Hormone Therapy
- Target testosterone: normal physiological male range (350–700 ng/dL) 2.
- For testosterone enanthate/cypionate injections, measure testosterone midway between injections; adjust dose if level is >700 ng/dL or <350 ng/dL 2.
- Research demonstrates that subcutaneous and intramuscular testosterone achieve similar therapeutic levels, with median total testosterone of 521–627 ng/dL 3, 4, 5.
Monitoring approach:
- Measure serum testosterone every 2–3 months until levels stabilize in the normal male range 2.
- During the first 3–9 months, total testosterone may appear elevated while free testosterone remains normal due to high SHBG levels in some biological females 2.
- Monitor for menstrual cessation (typically achieved within 2.9–6 months) and estradiol suppression to <50 pg/mL 4, 6.
Common Pitfalls
- Confusing MTF and FTM populations: Transgender women require testosterone suppression to <55 ng/dL, while transgender men require testosterone elevation to 350–700 ng/dL 2, 1.
- Timing of testosterone measurement matters: For injectable testosterone in FTM individuals, always measure midway between injections to avoid falsely elevated or suppressed values 2.
- Ignoring clinical symptoms: Laboratory values alone are insufficient; persistent androgenic symptoms in MTF individuals warrant therapy adjustment regardless of a single low testosterone reading 1.