People with gender dysphoria who self-prescribe cross-sex hormones: prevalence, sources, and side effects knowledge.

INTRODUCTION: There is a scarcity of research into the use of non-physician-sourced cross-sex hormones in the transgender population. However, when medication is not prescribed by health professionals, users' knowledge of such medication may be adversely affected.

AIMS: This study aims to define the prevalence of Internet-sourced sex hormone use in a population attending for initial assessment at a gender identity clinic, to compare the prevalence between gender-dysphoric men and women, and to compare knowledge of cross-sex hormone side effects between users who source cross-sex hormones from medical doctors and those who source them elsewhere.

METHODS: In the first part of the study, a cross-sectional design is used to measure the overall prevalence of sex hormone use among individuals referred to a gender clinic. The second part is a questionnaire survey aiming at measuring sex hormone knowledge among individuals referred to this clinic.

MAIN OUTCOME MEASURES: Main outcome measures were (i) categorical data on the prevalence and source of cross-sex hormone use and (ii) knowledge of sex hormone side effects in a population referred to a gender clinic.

RESULTS: Cross-sex hormone use was present in 23% of gender clinic referrals, of whom 70% sourced the hormones via the Internet. Trans men using testosterone had a sex hormone usage prevalence of 6%; one-third of users sourced it from the Internet. Trans women had a sex hormone usage prevalence of 32%; approximately 70% of users sourced hormones from the Internet. Cross-sex hormone users who sourced their hormones from physicians were more aware of side effects than those who used other sources to access hormones.

CONCLUSION: One in four trans women self-prescribe cross-sex hormones before attending gender clinics, most commonly via the Internet. This practice is currently rare among trans men. Self-prescribing without medical advice leaves individuals without the knowledge required to minimize health risks.