What initial evaluation is required before starting testosterone therapy in a post‑pubertal female‑to‑male transgender adolescent?

Initial Evaluation for Female-to-Male Transgender Adolescent Starting Testosterone

Before initiating testosterone therapy in a post-pubertal female-to-male transgender adolescent, perform baseline laboratory testing including complete blood count (hematocrit), lipid panel, liver function tests, and baseline testosterone levels, along with screening for contraindications such as polycythemia, thromboembolic risk factors, and liver disease. 1, 2, 3

Baseline Laboratory Assessment

Prior to testosterone initiation, obtain the following laboratory studies:

• Complete blood count with hematocrit - Testosterone increases red blood cell mass and can cause polycythemia, requiring baseline measurement 2, 3
• Lipid panel - Monitor for metabolic risk factors, as testosterone can affect lipid profiles 1
• Liver function tests - Screen for hepatic abnormalities before starting high-dose androgen therapy 1
• Baseline testosterone level - Document pre-treatment hormonal status 2

Medical History and Risk Factor Screening

Evaluate for absolute and relative contraindications:

• Cardiovascular history - Testosterone should not be initiated within 3-6 months of cardiovascular events (myocardial infarction, stroke) 2, 3
• Thromboembolic risk - Screen for personal or family history of deep vein thrombosis, pulmonary embolism, or thrombophilic disorders 1, 3
• Liver disease - Identify any hepatic dysfunction or focal nodular hyperplasia, which may affect route of administration 1
• Polycythemia history - Pre-existing elevated hematocrit is a relative contraindication 3

Fertility Counseling

Counsel the adolescent that exogenous testosterone suppresses spermatogenesis through feedback inhibition of pituitary FSH and may impair future fertility. 2, 3 This discussion must occur before treatment initiation, as testosterone should not be prescribed to individuals currently trying to conceive 2.

Physical Examination

Document baseline secondary sexual characteristics:

• Tanner staging - Confirm post-pubertal status (Tanner stage completion) 1, 4
• Baseline body composition - Document fat and muscle distribution for monitoring masculinization effects 5, 6
• Blood pressure and cardiovascular assessment - Establish baseline given cardiovascular risks 1, 3

Psychosocial Assessment

While not strictly a medical evaluation component, confirm:

• Persistent gender dysphoria - The adolescent should meet diagnostic criteria for gender incongruence and have long-lasting, intense gender dysphoria 4
• Mental health screening - Address any concurrent mental health issues before initiating hormonal therapy 4
• Informed consent - Ensure the adolescent and caregiver understand potential effects, including reproductive implications 4

Dosing and Monitoring Plan

After baseline evaluation is complete and no contraindications exist:

• Starting dose: Testosterone gel 1.62% at 40.5 mg (2 pump actuations) applied once daily to shoulders and upper arms, OR intramuscular testosterone at age-appropriate doses 3, 5
• Recheck testosterone levels at 2-3 months after initiation, targeting mid-normal male range (450-600 ng/dL) 2
• Monitor hematocrit at 3-6 months after starting treatment, then annually 3
• Once stable, monitor every 6-12 months with testosterone levels and hematocrit 2

Critical Pitfalls to Avoid

• Do not use oral alkylated testosterone - These formulations carry significant hepatotoxicity risk 2
• Do not skip cardiovascular screening - Testosterone therapy carries cardiovascular risks, particularly with injectable formulations that cause greater fluctuations in levels 2
• Do not neglect fertility counseling - This is an irreversible effect that must be discussed before treatment 2, 3
• Do not apply testosterone gel to genitals, chest, abdomen, or axillae - Application should be limited to shoulders and upper arms to minimize transfer risk and optimize absorption 3