About 24 % of transfeminine people in this cohort study had problematic drug use.

About 27 % of transfeminine people in this cohort study had problematic alcohol use.

Medical gender affirmation may be protective for problematic drug and alcohol use.

To estimate the association between medical and legal gender affirmation with problematic substance use among transfeminine adults.

Data from a longitudinal cohort (The LITE Study) were analyzed (n = 1186). Participants were enrolled between March 2018 and August 2020 and followed for 2 years. We tested the association between baseline medical and legal gender affirmation with problematic drug use (DAST-10 ≥3) and problematic alcohol use (AUDIT-C≥4) at 12-months. We used Poisson regression to estimate adjusted prevalence ratios (aPR) and 95 % confidence intervals (CI).

Mean age was 31.0 years (standard deviation=11.2). For race and ethnicity, 55.8 % were non-Latinx, white, 13.0 % were non-Latinx Black/African American, 17.1 % were Latinx, and 14.1 % were Asian, American Indiana/Alaskan Native, Native Hawaiian/Pacific Islander, or multiracial. For exposures, 75.1 % had met need for medical gender affirmation, 16.4 % did not seek medical gender affirmation, 8.5 % had unmet need for medical gender affirmation, and 19.5 % had all IDs match their chosen name/gender. At follow-up, 24.1 % had problematic drug use, and 27.6 % had problematic alcohol use. Participants with met need for medical gender affirmation were less likely to have problematic drug use at follow-up (aPR=0.70, 95 %CI=0.49˗0.99) compared to those with unmet need. Compared to those who did not seek medical gender affirmation, those with met need (aPR=0.72, 95 %CI=0.57˗0.91) and unmet need (aPR=0.68, 95 %CI=0.47˗0.97) were less likely to have problematic alcohol use.

Medical gender affirmation appears protective against problematic substance use. Increasing access to medical gender affirmation may improve substance use outcomes among transfeminine adults who desire such services.

Transgender

Medical gender affirmation

Legal gender affirmation

Problematic drug use

Problematic alcohol use

© 2025 The Authors. Published by Elsevier B.V.