SUN-502 Low-Dose Testosterone in Non-binary Individuals: A Retrospective Cohort Study

Abstract B.J. Nolan: None. A.S. Cheung: None. S. Zwickl: None. Background: Current guidelines for initiation of testosterone for gender affirmation are based on the assumption that trans individuals desire both rapid and complete masculinisation. However, an increasing number of trans individuals, particularly those with a non-binary gender identity, desire lower testosterone doses than recommended in existing guidelines. We aimed to assess the initiation and maintenance of low-dose testosterone in non-binary individuals treated with transdermal testosterone for ≥6 months. Methods: We performed a retrospective cohort study of non-binary individuals initiating low-dose transdermal testosterone. We included non-binary individuals initiating low-dose transdermal testosterone with ≥6 months follow-up. Primary outcomes were transdermal testosterone dose and serum total testosterone concentration. Results: Forty-six non-binary individuals treated with testosterone for at least 6 months were included. Median age was 27 years (24-30) and median duration of testosterone was 14 months (9-24). Median testosterone dose at initiation was 25 mg (12.5-50) and 37.5 mg (25-50) at last follow-up (p<0.01). Median serum total testosterone concentration was 11 nmol/L (5.2-15.7). By last follow-up, 40 (87%) remained on low-dose testosterone and 6 (13%) had increased to full-dose testosterone. In a subgroup of 30 individuals with ≥12 months testosterone treatment, 26 (87%) remained on low-dose testosterone at last follow-up. Three (7%) individuals had polycythaemia (haematocrit >0.5). Conclusion: Most non-binary individuals initiating low-dose transdermal testosterone continue testosterone doses lower than those recommended in current consensus guidelines. Future research should evaluate the influence of low-dose testosterone on clinical outcomes in non-binary people. Sunday, June 2, 2024