Efficacy of Sex Steroid Therapy Without Progestin or GnRH Agonist for Gonadal Suppression in Adult Transgender Patients.

CONTEXT: Testosterone (T) or estradiol (E2) are administered to suppress gonadal function in female-to-male (FTM) and male-to-female (MTF) transgender patients. How often sex steroids cause adequate suppression without GnRH agonist (GnRHa) or progestin therapy has not been reported. OBJECTIVES: (1) To determine how often T and E2 therapy alone can effectively suppress gonadal function in MTF and FTM transgender patients, and (2) to determine the frequency and range of serum E2 levels above the normal male range in FTM patients receiving T therapy. DESIGN: Retrospective cohort study. SETTING: Outpatient reproductive endocrinology clinic at an academic medical center. PATIENTS: A total of 65 FTM and 33 MTF patients were included who were > 18 years of age and not receiving progestin or GnRHa therapy. INTERVENTION: Female-to-male patients were receiving T through injections or gel. Male-to-female patients were receiving oral or subcutaneous E2. MAIN OUTCOME MEASUREMENTS: In FTM patients the indicator of ovary suppression was amenorrhea. In MTF patients, the indicator of testes suppression was T levels <50 ng/dL. RESULTS: Median serum total T level for FTM patients was 712 ng/dL (range, 370-1164 ng/dL). On T therapy alone, 90.8% of patients achieved amenorrhea and 49.2% of patients had serum E2 levels above the normal range for women. For MTF patients, the median serum E2 level was 129.2 pg/mL (range, 75-197 pg/mL). On E2 therapy alone, 84.8% of MTF patients had adequate suppression of testicular function. CONCLUSIONS: Testosterone and E2 therapy are usually effective without progestin or GnRHa therapy to suppress gonadal function in transgender patients. Progestin and/or GnRHa therapy should only be initiated in those patients who do not have adequate gonadal suppression on optimized doses of T or E2 alone.

Subcutaneous Injection of Testosterone Is an Effective and Preferred Alternative to Intramuscular Injection: Demonstration in Female-to-Male Transgender Patients.

Context: Testosterone (T) is commonly administered intramuscularly to treat hypogonadal males and female-to-male (FTM) transgender patients. However, these injections can involve significant discomfort and may require arrangements for administration by others. Objective: We assessed whether T could be administered effectively and safely subcutaneously as an alternative to intramuscular (IM) injections. Design: Retrospective cohort study. Setting: Outpatient reproductive endocrinology clinic at an academic medical center. Patients: Sixty-three FTM transgender patients aged >18 years electing to receive subcutaneous (SC) T therapy for sex transition were included. Fifty-three patients were premenopausal. Intervention: Patients were administered T cypionate or enanthate weekly at an initial dose of 50 mg. Dose was adjusted if needed to achieve serum total T levels within the normal male range. Main Outcome Measurements: Serum concentrations of free and total T and total estradiol (E2), masculinization, and surveillance for reactions at injection sites. Results: Serum T levels within the normal male range were achieved in all 63 patients with doses of 50 to 150 mg (median, 75/80 mg). Therapy was effective across a wide range of body mass index (19.0 to 49.9 kg/m2). Minor and transient local reactions were reported in 9 out of 63 patients. Among 53 premenopausal patients, 51 achieved amenorrhea and 35 achieved serum E2 concentrations <50 pg/mL. Twenty-two patients were originally receiving IM and switched to SC therapy. All 22 had a mild (n = 2) or marked (n = 20) preference for SC injections; none preferred IM injections. Conclusions: Our observations indicate that SC T injections are an effective, safe, and well-accepted alternative to IM T injections.