title: Subcutaneous Injection of Testosterone Is an Effective and Preferred Alternative to Intramuscular Injection: Demonstration in Female-to-Male Transgender Patients.
abstract: 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.
  
  
  
  We assessed whether T could be administered effectively and safely subcutaneously as an alternative to intramuscular (IM) injections.
  
  
  
  Retrospective cohort study.
  
  
  
  Outpatient reproductive endocrinology clinic at an academic medical center.
  
  
  
  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.
  
  
  
  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.
  
  
  
  Serum concentrations of free and total T and total estradiol (E2), masculinization, and surveillance for reactions at injection sites.
  
  
  
  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.
  
  
  
  Our observations indicate that SC T injections are an effective, safe, and well-accepted alternative to IM T injections.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Maine Medical Center, Portland, Maine 04102.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Spratt
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Maine Medical Center, Portland, Maine 04102.
authors.forename: India I
authors.initials: II
authors.lastname: Stewart
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Maine Medical Center, Portland, Maine 04102.
authors.forename: Clara
authors.initials: C
authors.lastname: Savage
authors.affiliation: Maine Medical Center Research Institute, Scarborough, Maine 04704.
authors.forename: Wendy
authors.initials: W
authors.lastname: Craig
authors.affiliation: Division of Endocrinology, Boston Children's Hospital, Boston, Massachusetts 02115.
authors.forename: Norman P
authors.initials: NP
authors.lastname: Spack
authors.affiliation: LabCorp, Calabasas, California 91301.
authors.forename: Donald Walt
authors.initials: DW
authors.lastname: Chandler
authors.affiliation: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Maine Medical Center, Portland, Maine 04102.
authors.forename: Lindsey V
authors.initials: LV
authors.lastname: Spratt
authors.affiliation: Department of Pediatrics, Division of Pediatric Endocrinology, Maine Medical Center, Portland, Maine 04102.
authors.forename: Toni
authors.initials: T
authors.lastname: Eimicke
authors.affiliation: Department of Pediatrics, Division of Pediatric Endocrinology, Maine Medical Center, Portland, Maine 04102.
authors.forename: Jerrold S
authors.initials: JS
authors.lastname: Olshan
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D017698:Postmenopause / Q000187:drug effects; D017697:Premenopause / Q000187:drug effects; D012189:Retrospective Studies; D013739:Testosterone / Q000008:administration & dosage* / Q000097:blood; D063106:Transgender Persons
chemical_list: D013739:Testosterone