Biomarkers in aging are measurable indicators that reflect biological age and physiological processes underlying aging, not just chronologically. This includes markers of molecules, cells, and function, such as telomer length, inflammatory markers, epigenetic changes, and metabolic profiles. Reliable biomarkers can help in early detection of age-related diseases, monitoring the efficacy of anti-agent therapy, and assessing the general health of individuals. Advances in diagnostic equipment and technology enable accurate and personalized approaches to replace alternative research and care, supporting efforts to expand health coverage and prevent age-related declines.