Purpose: Development of incongruent secondary sex characteristics in transgender youth can intensify or trigger the onset of
gender dysphoria. Guidelines from professional organizations recommend
gonadotropin-releasing hormone agonists, including
histrelin implants (Vantas and SupprelinLA) to suppress endogenous puberty. Although Vantas does not have a pediatric indication, it is anecdotally being used in pediatric gender centers throughout the United States because of its substantially lower cost. This retrospective study aimed to determine if both implants were effective in suppressing the hypothalamic-pituitary-gonadal axis in early-to-mid pubertal youth with
gender dysphoria. Methods: Youth with
gender dysphoria receiving care at the Center for Transyouth Health and Development at Children's Hospital Los Angeles (CHLA) or participants from an ongoing observational trial with a
histrelin implant placed for pubertal suppression at Tanner stage 2 or 3 were included. Sex
steroid (
testosterone or
estradiol) and
gonadotropin measurements at baseline (T0) and then 2 to 12 months following implant placement (T1) were abstracted from medical records. Results: Of the 66 eligible participants, 52% were designated female at birth. Most participants were white (60.6%). Twenty participants (30.3%) had a Vantas implant and 46 (69.7%) had a SupprelinLA implant. Mean age of insertion was 11.3 years.
Gonadotropin and sex
steroid levels were significantly decreased at T1 (2-12 months after insertion of implant), with no differences between implants. Conclusion: These results indicate that both implants are effective in suppressing puberty in early-to-mid pubertal youth with
gender dysphoria. These data may inform decisions about insurance coverage of
Supprelin and/or Vantas for youth with
gender dysphoria.