Is progesterone required for a female to male (FtM) transgender patient undergoing hormone therapy?

Progesterone is NOT Required for Female-to-Male Transgender Patients

Progesterone has no role in female-to-male (FtM) transgender hormone therapy and should not be prescribed. 1

Standard Hormone Therapy for FtM Patients

The cornerstone of FtM transition is testosterone therapy alone, without any need for progesterone or other hormones. 1, 2

Testosterone Regimen

• Target testosterone levels between 300-1,000 ng/dL (the physiological range for cisgender men), with the Endocrine Society recommending the mid-normal range to optimize safety and efficacy. 1

• Injectable testosterone (cypionate or enanthate) is the most common formulation, administered intramuscularly or subcutaneously every 1-2 weeks at 200 mg per dose. 1, 3

• Transdermal testosterone gel (1.62%, starting at 40.5 mg daily) is the most effective non-injectable option for patients with needle phobia, though it carries lower risk of erythrocytosis compared to injectable forms. 1

• Avoid testosterone undecanoate due to concerns for pulmonary oil microembolism and anaphylaxis. 4, 1

Expected Physical Changes

Testosterone therapy alone produces complete masculinization without any need for additional hormones: 1, 5

• Voice deepening due to thickened vocal cords
• Facial and body hair growth
• Menstrual suppression (typically achieved within 3-6 months)
• Clitoral growth (maximum length of approximately 4.6 cm achieved by 1 year) 3
• Increased muscle mass and strength (15% increase in quadriceps cross-sectional area and thigh muscle volume) 4
• Decreased fat mass with male pattern body composition changes
• Increased libido 1

Why Progesterone is Not Used

Progesterone is only relevant in male-to-female (MtF) transgender medicine, and even there it is NOT recommended. 4

• The Endocrine Society explicitly does not recommend progestins for transgender women due to increased risk of breast cancer, thromboembolism, and stroke. 4

• A retrospective review found that transgender women did not derive benefit from progesterone, with some discontinuing due to absence of measurable effects or poor mood. 4

• Progesterone has no physiological role in masculinization and would be counterproductive in FtM patients seeking testosterone-driven virilization. 6, 7

Critical Monitoring Parameters

Pre-Treatment Screening

• Screen for liver abnormalities and polycythemia before initiating testosterone therapy. 4, 1

Ongoing Monitoring (Every 3 Months First Year, Then Every 6-12 Months)

• Monitor for erythrocytosis/polycythemia, particularly common with injectable formulations; if hematocrit rises above normal male reference range, consider temporarily withholding therapy, reducing dose, performing phlebotomy, or switching to transdermal route. 1

• Check blood pressure regularly, as testosterone may increase blood pressure. 1

• Monitor lipid profiles, as testosterone may increase triglycerides and LDL cholesterol while decreasing HDL. 1, 3

• Verify testosterone trough levels remain 300-1,000 ng/dL. 1

Common Pitfalls to Avoid

• Avoid supraphysiologic testosterone dosing, which increases risk of adverse effects without additional benefit. 1

• Do not add progesterone or other hormones to the testosterone regimen—testosterone alone is sufficient and appropriate. 1, 2

• Inadequate testosterone dosing can negatively impact bone density, making appropriate dosing and monitoring essential. 4, 1

• Watch for androgenic alopecia and acne, which are common side effects. 1

• Monitor for gynecological effects including pelvic pain and genital dryness. 1