Testosterone Management in Female-to-Male Transition
These testosterone levels (total testosterone 503 ng/dL and free testosterone 14.5 ng/dL) are within the target physiologic male range and should be maintained at current dosing, with monitoring every 6-12 months to ensure stability. 1
Target Testosterone Levels for Gender-Affirming Hormone Therapy
The goal of testosterone therapy in female-to-male transition is to achieve testosterone levels in the normal physiologic male range:
- Target total testosterone: 450-600 ng/dL (middle tertile of normal male range) 1
- Normal male reference range: 300-800 ng/dL 1
- Your patient's level of 503 ng/dL falls appropriately within this target range 1
The free testosterone level of 14.5 ng/dL also appears appropriate, as this represents the metabolically active fraction that drives masculinization effects. 2
Monitoring Recommendations
Current dosing should be maintained since levels are at goal. The monitoring schedule should follow these parameters:
- Measure testosterone levels every 6-12 months once stable levels are confirmed on a given dose 1
- Testosterone should be measured in a fasting morning sample for accuracy 3, 4
- For injectable testosterone: measure levels midway between injections, targeting 500-600 ng/dL 1
- For transdermal preparations: levels can be measured at any time, though peak values occur 6-8 hours after application 1
Dosing Principles
Use the minimal dosing necessary to maintain testosterone levels in the normal physiologic range of 450-600 ng/dL 1. Since your patient is already at 503 ng/dL, no dose adjustment is needed. 1
If the patient were not experiencing adequate masculinization despite achieving target testosterone levels, therapy should be reassessed rather than increasing the dose above physiologic male ranges. 1
Safety Monitoring Considerations
While these guidelines are derived from cisgender male testosterone replacement literature, the same safety principles apply:
- Screen for cardiovascular risk factors including dyslipidemia, hypertension, diabetes, and smoking 5
- Measure hemoglobin at baseline and during follow-up, as testosterone increases hemoglobin levels 5
- Counsel about cardiovascular symptoms (chest pain, shortness of breath, dizziness) and advise reporting these immediately 5
- Counsel that fertility will be impaired while on testosterone therapy, as exogenous testosterone suppresses spermatogenesis 5
Common Pitfalls to Avoid
- Do not increase dosing above physiologic male ranges (>600 ng/dL target) simply to achieve faster or more complete masculinization 1
- Do not measure testosterone at random times - morning fasting samples provide the most accurate assessment 3, 4
- Do not use single measurements - testosterone levels vary substantially over time due to biologic factors 4