The duration of treatment for which a physician may prescribe a medicine, ‘prescription duration’, is often dispensed at the pharmacy on multiple occasions of shorter time periods, ‘dispensing duration’. These durations vary significantly between and within countries. In Australia, the quantity of medication supplied at each dispensing has recently been extended from 30 to 60 days for a selection of medicines used for chronic health conditions, such as diabetes and hypertension. Dispensing durations vary between countries, with 30, 60 or 90 days being the most common—with 90 days aligning with the recommendation of the 2023 Global Report on Hypertension from the World Health Organization. The full impact of shorter vs longer prescription durations on health costs and outcomes is unknown, but current evidence suggests that 90-day dispensing could reduce costs and improve patient convenience and adherence. More rigorous research is needed.