Introduction Polypharmacy is common among individuals with multimorbidity, often leading to inappropriate medication use and is associated with an increased risk of frailty, hospitalisation and mortality. Structured medication reviews (SMRs) have emerged as a promising method for optimising medication use. However, research examining their efficacy is limited. This review aims to evaluate the impact of SMRs on improving outcomes for adults with multimorbidity and polypharmacy in primary care settings. Additionally, this review seeks to identify prevailing patterns and trends in the mode of delivery of SMRs.

Methods and analysis A systematic review will be conducted using Ovid MEDLINE, Ovid EMBASE, Web of Science and CINAHL (1997–present). Primary outcomes will include medication-related measures such as dose, frequency and dosage form. Secondary outcomes under investigation will include physical, mental, functional and health service outcomes, as reported. Two independent reviewers will conduct the screening and data extraction, resolving disagreements through discussion. Once eligible studies are identified, the extracted data will be summarised in tabular format. The risk of bias in the articles will be assessed using either the Cochrane Risk of Bias 2 tool or the Newcastle-Ottawa scale, depending on the design of the studies retrieved. Subgroup analysis will be performed using demographic variables and modes of delivery where the data supports. If appropriate, a meta-analysis of the data extracted will be conducted to determine the impact of the SMRs on reported outcomes. If a meta-analysis is not possible due to heterogeneity, a narrative synthesis approach will be adopted.

Ethics and dissemination This proposed review is exempt from ethical approval as it aims to collate and summarise peer-reviewed, published evidence. This protocol and the subsequent review will be disseminated in peer-reviewed journals, conferences and patient-led lay summaries.

PROSPERO registration number CRD42023454965.