Initiation and Maintenance of Low‐Dose Transdermal Testosterone in Non‐Binary Individuals: A Retrospective Audit

Objective An increasing number of trans individuals, particularly those who are non‐binary, desire lower testosterone doses than those outlined in current guidelines for gender affirmation. These guidelines acknowledge the need for a tailored approach to treatment, especially for non‐binary people. However, existing guidelines for initiation of testosterone assume that trans individuals desire rapid and complete masculinisation through standard dosing. We aimed to assess the initiation and maintenance of low‐dose testosterone in non‐binary individuals treated with transdermal testosterone for ≥ 6 months. Design Retrospective audit. Patients Non‐binary individuals initiating low‐dose transdermal testosterone with ≥ 6 months follow‐up. Intervention Testosterone 1% gel (< 50 mg daily) or testosterone 5% cream (< 100 mg daily). Measurements Transdermal testosterone dose and serum total testosterone concentration. Results Forty‐six individuals were included. Median age was 27 years (24−30) and duration of testosterone was 14 months (9−24). For individuals treated with testosterone 1% gel, median dose at initiation was 12.5 mg (12.5−25) and 25 mg (20.4−37.5) at last follow‐up ( p < 0.01), and for those treated with testosterone 5% cream, the median dose at initiation was 50 mg (31.3−50) and 50 mg (50−68.8) at last follow‐up ( p = 0.02). Median serum total testosterone concentration was 11 nmol/L (5.2−15.7). By the 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 treatment, 26 (87%) remained on low‐dose testosterone by last follow‐up. Three (7%) individuals had polycythemia (haematocrit > 0.5). Conclusions Most non‐binary individuals initiating low‐dose transdermal testosterone continue doses lower than those recommended in current guidelines after 6−12 months of treatment. These hypothesis‐generating findings highlight the need for studies evaluating the influence of low‐dose testosterone on clinical outcomes and safety end‐points.