In this blog, Dave Taylor and Jackie Martin-Kerry discuss the CHARMER (CompreHensive geriAtRician led MEdication Review) trial, registered at the ISRCTN registry. The trial, which began on 1 February 2024, will be the largest trial within the Ageing Specialty of the Clinical Research Network’s portfolio across England, involving data from over 20,000 older inpatients across 24 hospitals. Internationally, it will be the largest deprescribing trial.