Testosterone Gel Dosing and Monitoring Guidelines for Transgender Men

Dose Initiation and Titration

• The Endocrine Society recommends starting testosterone gel at 40.5 mg (≈2 pump actuations) applied once daily to the shoulders and upper arms, with dose adjustments in 20.25 mg increments based on serum testosterone levels. 1
• The maximum approved daily dose of testosterone gel is 81 mg (≈4 pump actuations) to avoid supraphysiologic exposure and associated adverse effects. 2

Serum Testosterone Monitoring

• Measure serum testosterone every 2–3 months during the first year of therapy, then 1–2 times per year once levels are stable. 1
• Target testosterone concentrations within the normal physiological male range (approximately 300–1,000 ng/dL). 1
• For transdermal formulations, a reliable testosterone measurement can be obtained after at least 1 week of consistent daily dosing. 1

Hematocrit and Erythrocytosis Surveillance

• Perform a complete blood count at baseline, every 3 months during the first year, and then 1–2 times annually thereafter. 1
• Higher gel doses (≈100 mg/day delivering ≈10 mg/day) were associated with erythrocytosis in 17.9 % of patients, compared with 2.8 % at lower doses, demonstrating a dose‑dependent risk. 2
• Switching from injectable to transdermal testosterone can reduce the risk of erythrocytosis. 3

Estradiol Monitoring

• Measure estradiol during the first 6 months of testosterone therapy (or until uterine bleeding has ceased for 6 months); aim for estradiol levels < 50 pg/mL. 1

Liver and Metabolic Monitoring

• Check liver function tests at baseline, every 3 months for the first year, then 1–2 times annually. 1
• Regularly assess weight, blood pressure, lipid profile, and fasting glucose at routine visits. 1

Safety Considerations Related to Dose

• Supraphysiologic testosterone levels increase the risk of erythrocytosis, cardiovascular events, and other adverse outcomes; the 81 mg maximum dose was established to keep these risks within an acceptable safety profile. [2][3]

Pregnancy and Teratogenicity

• Testosterone therapy suppresses ovulation but is not a reliable contraceptive and is teratogenic; women who are pregnant or attempting conception should avoid exposure. 1