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

J Clin Endocrinol Metab. 2017 Jul 1;102(7):2349-2355. doi: 10.1210/jc.2017-00359.

Abstract

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.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Analysis of Variance
  • Body Mass Index
  • Cohort Studies
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Female
  • Humans
  • Injections, Intramuscular
  • Injections, Subcutaneous
  • Male
  • Middle Aged
  • Patient Safety
  • Postmenopause / drug effects
  • Premenopause / drug effects
  • Retrospective Studies
  • Testosterone / administration & dosage*
  • Testosterone / blood
  • Transgender Persons*

Substances

  • Testosterone