Polypharmacy, i.e. the concomitant taking of several medicines, is common for older people. It has been associated with increased risks of non-adherence, inappropriate medicines, interactions, side effects and geriatric syndrome. A medicinal product is inappropriate when it proves to be ineffective or its potential inconvenience outweigh the expected benefits. Deprescription aims to reduce inappropriate medicines in order to reduce the risks associated with polypharmacy and improve people’s well-being. Deprescription should be patient-centred and carried out in collaboration with the patient and their relatives. However, its location faces barriers in patients and their relatives. However, few studies have been published on this subject. We offer a synthesis of qualitative, quantitative or mixed scientific studies exploring the factors influencing older people and their relatives in relation to polypharmacy or deprescription. Research into relevant studies was carried out using bibliographic databases and study reference lists included. Studies of older patients (65 +) or their relatives in the factors influencing them in the face of polypharmacy or deprescription were selected. The convergent thematic synthesis identified common sub-themes and descriptive themes on the basis of which an analytical construction was developed. 21 studies have been included, focusing on patients’ attitudes to stopping potentially inappropriate medicines. The perceived efficacy of medicines and their side effects as well as the patient-prescribing relationship are the factors most frequently mentioned in the studies included. Highly interdependent factors shape patients’ attitudes towards polypharmacy or deprescription. A full understanding of the barriers and facilitators to optimise the medicine diet is essential for the development of targeted interventions to reduce inappropriate medicines and associated risks.