What is the recommended Hormone Replacement Therapy (HRT) regimen for female-to-male transition?

Hormone Replacement Therapy for Female-to-Male Transition

For transgender men (female-to-male), the recommended hormone replacement therapy regimen is testosterone administration with a target level of 300-1,000 ng/dL to induce virilization and suppress feminizing characteristics. 1

Testosterone Options and Administration

• Injectable testosterone is the most commonly used formulation, with options including:

  • Testosterone enanthate or cypionate: 50-100 mg weekly or 100-200 mg every 2 weeks, administered intramuscularly or subcutaneously 1, 2
  • Testosterone undecanoate (long-acting): Available in some countries but requires risk monitoring due to potential pulmonary oil microembolism and anaphylaxis 1

• Topical testosterone options include:

  • Testosterone gel: Applied daily to skin 2, 3
  • Testosterone patches: Applied daily to skin 3

Expected Physical Changes

• Testosterone therapy induces virilization with effects including:

  • Voice deepening 1
  • Increased muscle mass and strength (15% increase in quadriceps cross-sectional area) 1
  • Redistribution of body fat 1, 2
  • Increased body and facial hair 2
  • Clitoral enlargement 2
  • Cessation of menses 2

• Timeline for changes:

  • Initial changes visible within 6 months of therapy 2
  • Maximum virilization effects typically achieved after 3-5 years of consistent use 2

Monitoring Protocol

• Before initiating therapy:

  • Complete baseline assessment including complete blood count, liver function, lipid profile, and baseline hormone levels 4
  • Screen for contraindications including erythrocytosis, severe liver dysfunction, or unstable cardiovascular disease 1

• During therapy:

  • Monitor every 3 months during the first year, then every 6-12 months 2
  • Maintain testosterone levels within male physiological range (300-1,000 ng/dL) 2
  • Monitor hematocrit/hemoglobin (risk of erythrocytosis) 1
  • Monitor lipid profile (potential increases in triglycerides and LDL, decreases in HDL) 1

Potential Risks and Management

• Erythrocytosis: Most common laboratory abnormality 1

  • Management options include reducing testosterone dose, switching to transdermal formulation, smoking cessation, or weight loss if BMI is high 1

• Cardiovascular considerations:

  • Testosterone may increase blood pressure and alter lipid profiles 1
  • Current evidence suggests no significant increase in cardiovascular mortality in transgender men 1

• Bone health:

  • Inadequate testosterone dosing may negatively impact bone density 1
  • Monitor bone mineral density if signs of hypogonadism develop 1

• Reproductive considerations:

  • Discuss fertility preservation options before starting therapy 1
  • Testosterone is not a reliable contraceptive; pregnancy can still occur 1

Common Pitfalls and Caveats

• Inconsistent dosing can lead to mood fluctuations, particularly with injectable formulations that may create a "roller coaster" effect of alternating symptomatic benefit and return to baseline symptoms 1

• Testosterone therapy should not be initiated without proper psychological evaluation and diagnosis of gender dysphoria/gender incongruence 4

• Patients should be counseled that some changes (voice deepening, clitoral growth, facial hair) are irreversible even if testosterone is discontinued 4

• Regular monitoring is essential as long-term effects of testosterone in transgender men are still being studied 3

• Transgender men who have not undergone hysterectomy should continue appropriate gynecological cancer screening 1

By following these guidelines and maintaining appropriate monitoring, testosterone therapy for transgender men is generally safe and effective, leading to significant improvements in quality of life and reduction in gender dysphoria 5.