Translation and interpreting services must be considered across the lifecycle of clinical trials

Background Inclusive clinical research requires that all prospective participants are provided with accessible, comprehensible information to support informed decision-making regarding trial participation. However, people with limited English proficiency (LEP) remain disproportionately excluded from trials in English-speaking countries, largely due to insufficient translation and interpretation support. This exclusion compromises equity, participant safety, and the integrity and generalisability of trial findings. Main body This commentary highlights why language support must be considered across the entire clinical trial lifecycle, rather than limited to recruitment and consent stages. We examine challenges including identifying which languages and materials require translation; quality assurance of translations; budgeting complexities; reliance on underqualified interpreters; and variability in provision across sites. Practical implications span recruitment, informed consent, outcome measures, intervention delivery, monitoring recruitment and retention, safety reporting, and communication to participants throughout the trial. We emphasise the need for early planning, transparent budgeting, robust quality standards, and researcher training. Drawing on existing frameworks and recent evidence, we provide recommendations on how sponsors, funders, healthcare providers, research teams, and research governance organisations can move towards more systematic and equitable approaches to translation and interpretation. Conclusion Addressing linguistic diversity in clinical trials requires a coordinated, lifecycle-wide strategy that goes beyond providing translated materials at the recruitment consultation. System-level changes, such as clear national standards, centralised models of provision, and better training are essential to reduce inequities and enhance the reliability of trial outcomes. Ensuring that people with LEP are supported throughout their participation will strengthen trust, improve safety, and contribute to more representative evidence for healthcare decision-making.