IntroductionPharmacist-led medication reviews are an established intervention to support patients prescribed multiple medicines or with complex medication regimes. For this systematic review, a medication review was defined as ‘a consultation between a pharmacist and a patient to review the patient’s total medicines use with a view to improve patient health outcomes and minimise medicines-related problems’. It is not known how varying approaches to medication reviews lead to different outcomes.AimTo explore the common themes associated with positive outcomes from pharmacist-led medication reviews.MethodRandomised controlled trials of pharmacist-led medication reviews in adults aged 18 years and over were included. The search terms used in MEDLINE, EMBASE and Web of Science databases were “medication review”, “pharmacist”, “randomised controlled trial” and their synonyms, time filter 2015 to September 2023. Studies published before 2015 were identified from a previous systematic review. Risk of bias was assessed using the Cochrane risk of bias 2 tool. Descriptions of medication reviews’ components, implementation and outcomes were narratively synthesised to draw out common themes. Results are presented in tables.ResultsSixty-eight papers describing 50 studies met the inclusion criteria. Common themes that emerged from synthesis include collaborative working which may help reduce medicines-related problems and the number of medicines prescribed; patient involvement in goal setting and action planning which may improve patients’ ability to take medicines as prescribed and help them achieve their treatment goals; additional support and follow-up, which may lead to improved blood pressure, diabetes control, quality of life and a reduction of medicines-related problems.ConclusionThis systematic review identified common themes and components, for example, goal setting, action planning, additional support and follow-up, that may influence outcomes of pharmacist-led medication reviews. Researchers, health professionals and commissioners could use these for a comprehensive evaluation of medication review implementation.PROSPERO registration numberCRD42020173907.