Objective This study aims to implement a version of patient-centred labels (PCL) consistent with current labelling practice in Australia; assess the effectiveness of PCL in relation to the proportion of participants that correctly comprehend dosing instructions, and explore the proportion of correct comprehension of PCL in participants with both low and high health literacy. Design Randomised controlled trial. Setting A large tertiary care hospital in Brisbane, Queensland, Australia. Participants 121 participants with a majority born in Australia (65.3%), New Zealand (14.0%), the UK (6.6%) and Ireland (2.5%). Intervention Participants were randomly assigned to either a panel of three PCL (n=61) or three standard labels (n=60) and asked to comprehend their assigned panel of labels. Outcome measures Difference in the proportion of participants that correctly comprehend dosing instructions provided on PCL compared with standard labels. The two-proportion test was used to measure the impact of PCL on the proportion of participants correctly comprehending dosing instructions. Results A greater proportion of participants were able to accurately comprehend PCL compared with standard labels. The proportion of participants who were able to correctly comprehend dose instructions provided on all three labels was significantly higher in the group that received PCL; 23.3% standard vs 83.6% PCL, p$<$0.001. The effect was observed in both low and high health literacy participants. The proportion of participants with accurate label comprehension was higher in participants with low Newest Vital Signs scores (8.3% standard vs 85.7% PCL, p$<$0.001) and low Rapid Estimate of Adult Literacy in Medicine scores (10.5% standard vs 96.0% PCL, p$<$0.001) who received PCL. Conclusion This study supports the use of PCL in Australian pharmacy practice. PCL provide simple, clear and explicit dosing instructions to patients. Implementing PCL may reduce the risk of misinterpreting dosing instructions by patients and improve quality use of medicines. Trial registration number ACTRN12621000083897; Results.