Why Biological Age Testing?
Biological-age tests promise to replace your chronological age with a number that tracks how your body is actually aging — and how interventions are moving it. The category is now mature enough to ship real consumer products: TruDiagnostic, Elysium Index, Generation Lab, GlycanAge, MyDNAge, and Tally Health all bundle epigenetic methylation analysis (or glycan / multi-omic analogs) into a $200–$800 retail kit. What’s still messy is methodology: which clock, how many CpGs, what reference cohort, what reproducibility. A single number on a dashboard can hide enormous methodological variance.
What We Compare
Every test in our comparison is evaluated on:
- Clock methodology — first-generation (Horvath, Hannum), second-generation (PhenoAge, GrimAge), or third-generation pace-of-aging clocks (DunedinPACE). We surface which the test uses and what each is validated for.
- CpG resolution — number of methylation sites analyzed. TruDiagnostic’s ~950k CpG array is the highest-resolution consumer offering; smaller targeted arrays are cheaper but more sensitive to noise.
- Test-retest reproducibility — how stable is the result on the same blood drawn twice? TruDiagnostic publishes 99% reproducibility on its multi-clock; competitors vary.
- Sample collection — phlebotomist blood draw vs at-home fingerstick vs cheek swab. Saliva-based clocks are convenient but methodologically weaker.
- Longitudinal cost — biological age is meaningful as a trend, not a single point. We model 3-year cost for quarterly or semi-annual testing per provider.
- Reporting depth — single number, organ-system breakdown, or interpretation framework. Some tests are dashboards; others are PDFs.
Key Findings (2026)
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TruDiagnostic’s TruAge has the strongest published methodology. ~950,000 CpG sites, multi-clock approach (OMICmAge, SYMPHONYAge, exclusive DunedinPACE licensing), published with Harvard and Yale researchers. 99% test-retest reproducibility is best-in-class. Pricing reflects this — $399 per test at the entry tier.
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GlycanAge measures something different. Glycan analysis indexes immune-system aging via IgG glycosylation patterns, not DNA methylation. It complements rather than competes with epigenetic clocks; both have a place if you can afford parallel testing.
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Saliva-based tests (MyDNAge, Tally Health) are convenient but lower resolution. Cheaper and easier to ship, but published methylation-clock validation is stronger from blood than saliva. Acceptable for trend tracking; less reliable for single-point decisions.
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No consumer biological-age test is FDA-cleared. The FDA does not approve “biological age” as a clinical claim; tests ship as wellness products. This means lab quality (CLIA-certified processing) matters more than FDA status — confirm the partner lab.
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A single biological-age number is the wrong takeaway. The methodologically defensible signal is change over time on the same clock — not a one-shot age vs chronological. Plan for at least three measurements (baseline, 6-month, 12-month) before concluding anything about an intervention.
See our ranked best biological age tests guide for how the tests compare by method, resolution and price.
Who Should Read This
- Longevity-focused readers comparing epigenetic test providers
- Anyone tracking the impact of interventions (sleep, exercise, supplements, peptides) on aging biomarkers
- Buyers deciding between TruDiagnostic vs Elysium Index vs GlycanAge
- People who want to understand why “biological age” is a real signal but a slippery one