Pharmacoepidemiology of testosterone prescribing in Australia, 2010-2023.

OBJECTIVE: After decades of progressive increase, subsidized testosterone prescribing under the Pharmaceutical Benefits Scheme (PBS) in Australia reduced following tightening of prescribing criteria in 2015. Conversely, testosterone use as gender-affirming hormone therapy (GAHT) for transgender and gender-diverse individuals is increasing. This study aimed to investigate the longer-term impact of the 2015 tighter PBS regulations on testosterone prescribing in Australia and to characterize and quantify the potential expansion of testosterone prescribing for GAHT. DESIGN: Observational analysis of national testosterone prescribing under the Australian PBS. METHODS: Data for all PBS testosterone prescriptions from 2010 to 2023 were obtained. Data comprised the total number and cost of prescriptions for each testosterone product per month in each state and territory, designated by patient age, gender (mostly sex recorded at birth), prescriber type, and indication. Total use for each product was compared by converting prescriptions to defined monthly dosage. RESULTS: Male testosterone prescriptions rose to a peak in 2014, fell 30% to a nadir in 2016, and rose again to reach 98% of the 2014 peak in 2023. Most of the increase after 2016 resulted from a re-expansion of nonspecialist prescribing to those aged 40-79 years. Female testosterone prescriptions rose 80-fold from 2010 to 2023, mainly to individuals aged 18-29 years. In 2023, new female prescriptions accounted for 30% of all testosterone initiations. CONCLUSIONS: Male testosterone use is again approaching pre-2015 peak levels in Australia, potentially due to evasion of PBS regulations. The marked increase in female prescriptions likely reflects a rapid expansion of testosterone use as masculinizing GAHT. This highlights the growing need for accessible specialized gender-affirming care.