Testosterone and other treatments for transgender males and non-binary trans masculine individuals.

Testosterone can be administered via multiple routes including topical and injectable preparations for transgender males.

• Injectable preparations include testosterone enanthate, testosterone cypionate, and testosterone undecanoate
• Topical preparations include gels and creams applied to skin
• Subcutaneous pellets are also available in some regions
• The choice of preparation affects dosing frequency and pharmacokinetic profiles

Testosterone therapy results in significant masculinising physical changes in transgender males.

• Physical changes include voice deepening, clitoral enlargement, increased body and facial hair, and increased muscle mass
• Fat redistribution from gynoid to android pattern occurs with therapy
• Menstruation typically ceases with testosterone treatment
• Some changes such as voice deepening are irreversible, while others may be partially reversible upon cessation

Testosterone therapy has measurable effects on the cardiovascular system in transgender males.

• Testosterone therapy is associated with changes in lipid profiles, including increases in LDL and decreases in HDL cholesterol
• Hematocrit and hemoglobin levels increase with testosterone therapy, raising potential concern for polycythemia
• Blood pressure changes have been observed in some studies
• Long-term cardiovascular risk data remain limited, particularly for older transgender males

Testosterone therapy affects bone mineral density in transgender males.

• Testosterone therapy is associated with maintenance or increase in bone mineral density
• Pre-treatment bone density may be affected by prior estrogen suppression or pubertal suppression
• Regular monitoring of bone health is recommended as part of long-term follow-up
• The anabolic effects of testosterone on bone are considered protective against osteoporosis

Testosterone therapy has effects on the reproductive system, including impacts on fertility.

• Testosterone therapy suppresses ovulation and menstruation but is not a reliable contraceptive
• Fertility may be preserved if testosterone is discontinued, though evidence on long-term fertility outcomes is limited
• Individuals interested in future pregnancy should be counselled about fertility preservation prior to initiating therapy
• Uterine atrophy can occur with prolonged testosterone use

Testosterone therapy is associated with improvements in psychological wellbeing and quality of life.

• Studies report reductions in gender dysphoria following testosterone therapy
• Improvements in mental health outcomes including reduced anxiety and depression have been reported
• Quality of life measures improve with testosterone-induced masculinisation
• Psychological benefits are considered a primary goal of hormonal treatment

Long-term follow-up and monitoring are recommended for transgender males on testosterone therapy.

• Monitoring should include hematocrit, lipid profiles, liver function, and blood pressure
• Cervical and uterine cancer screening recommendations should be adapted for transgender males
• Breast cancer screening considerations remain relevant for those who have not undergone mastectomy
• Gaps remain in evidence for specific populations including older transgender males and those on low-dose testosterone

There are identified gaps in the evidence base for testosterone therapy in specific subpopulations of transgender males.

• Studies with longer follow-up periods are needed
• Evidence is limited for individuals who prefer low-dose testosterone regimens
• Data on transgender males interested in pregnancy during or after testosterone therapy are insufficient
• Research on older transgender individuals is particularly lacking