Follow monitoring protocol for transgender males on hormone therapy

STEP 1 — Gather Information

Collect baseline demographics, medical history, current testosterone formulation and dose, physical exam (Tanner stage, signs of virilization, acne, blood pressure), and baseline labs (total testosterone, hematocrit/hemoglobin, fasting lipid panel, liver enzymes, vitamin D).
Action: Schedule the first follow‑up visit in 3 months.

STEP 2 — Rule In / Rule Out

Measure hematocrit at baseline and every 3 months during the first year, then 1‑2 times per year thereafter.
Decision: If hematocrit ≥ 50% (or hemoglobin > 18 g/dL), rule in erythrocytosis; otherwise rule out.
Action: If hematocrit ≥ 50%, proceed to dose reduction or therapeutic phlebotomy; otherwise continue routine monitoring.

STEP 3 — Classify or Stratify

Assess serum testosterone level according to administration route: for enanthate/cypionate injections measure midway between injections; for gels measure ≥24 h after daily application; for undecanoate measure just before the next injection.
Classification: Sub‑therapeutic (<400 ng/dL), therapeutic (400‑700 ng/dL), supratherapeutic (>700 ng/dL).
Action: Adjust testosterone dose to maintain levels within the therapeutic range (400‑700 ng/dL).

STEP 4 — Decide

Based on testosterone classification and hematocrit result, decide on next steps: maintain current dose if therapeutic and hematocrit <50%; reduce dose if supratherapeutic or hematocrit ≥50%; hold therapy and evaluate for other causes if hematocrit >54%; consider phlebotomy if symptomatic erythrocytosis persists.
Action: Implement the decided dose adjustment and schedule the next laboratory check in 3 months if stable, or sooner if the dose was changed.

Clinical Guardrails / Mimics / Pitfalls

• Avoid supraphysiologic testosterone (>1000 ng/dL) to limit erythrocytosis, cardiovascular risk, and sleep apnea.
• Monitor fasting lipids and blood pressure every 3‑6 months; treat hypertension or dyslipidemia per standard guidelines.
• Assess for signs of sleep apnea (snoring, daytime somnolence) at each visit.
• Do not initiate testosterone in patients with uncontrolled hematocrit >54% without evaluation.
• If testosterone is stopped, obtain bone mineral density measurement when osteoporosis risk factors exist.
• Exclude pregnancy before starting therapy; note that transdermal testosterone requires application‑site rotation and level measurement no sooner than 1 week after daily application.
• Do not rely solely on symptoms; laboratory confirmation of testosterone and hematocrit is required for dose decisions.

Concrete Clinical Example

A 22‑year‑old transgender male begins testosterone enanthate 100 mg IM weekly. Baseline: testosterone 200 ng/dL, hematocrit 38%. At 3‑month visit, testosterone measured midway between injections is 620 ng/dL, hematocrit 44%, lipids unchanged. Classification: therapeutic; hematocrit <50%. Decision: maintain current dose. Next labs scheduled in 3 months.

Source: Endocrine Society Clinical Practice Guideline, “Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons,” Wylie C. Hembree et al., 2017, DOI: 10.1210/jc.2017-01658