Epigenetic clocks are research tools, not consumer health tests

Epigenetic aging clocks sold as “biological age” tests are powerful research tools for studying aging at the population level but unreliable for individuals: dozens of clocks can disagree, results vary by sample type and short-term factors, and there is no universal gold standard. They are not medical diagnostics and should be used by researchers to identify population-level lifestyle factors that slow aging or to test therapies, not for personal health decisions or insurance decisions, though future work may eventually inform individualized care.