# Biological age

Biological age is an estimate of how old your body seems to be. It is based on physiological and molecular markers, not on the calendar. You can derive it several ways. Options include blood biomarkers (like PhenoAge), DNA-methylation patterns (epigenetic clocks), grip strength, gait speed, or organ-specific protein signatures. It is widely used in longevity research. But no single biological-age measure is yet endorsed by regulators as a clinical endpoint. And how well each one is validated varies a lot.

## Sources

- Horvath S, Raj K. (2018). DNA methylation-based biomarkers and the epigenetic clock theory of ageing. Nature Reviews Genetics. https://doi.org/10.1038/s41576-018-0004-3
- Levine ME, Lu AT, Quach A, Chen BH, Assimes TL, Bandinelli S, et al.. (2018). An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY). https://doi.org/10.18632/aging.101414

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_Canonical: https://longevity-switzerland.com/en/glossary/biological-age · Part of Longevity Cities · Updated 2026-06-22_