Comparison

GrimAge vs DunedinPACE

Last updated Mon Jun 08 2026 00:00:00 GMT+0000 (Coordinated Universal Time)· 2 min read

What each measures

GrimAge estimates how old your body looks epigenetically — cumulative biological age. Calibrated using plasma protein surrogates and smoking-pack-years to predict mortality.
DunedinPACE estimates the rate of biological aging you are currently aging at. ~1.0 is average; <1 is slower than average; >1 is faster. Calibrated against the longitudinal Pace of Aging signal from the Dunedin Multidisciplinary Health and Development Study.

The difference matters: GrimAge tells you where you stand; DunedinPACE tells you which direction you are heading.

Predictive performance

GrimAge is the strongest single epigenetic-clock predictor of all-cause mortality in head-to-head cohort analyses.
DunedinPACE detects intervention effects on shorter time scales (months to a couple of years) better than cumulative-age clocks, which require longer follow-up to show change.

For intervention tracking

GrimAge: less responsive to short interventions; better for long-term tracking and overall risk stratification.
DunedinPACE: more responsive to intervention; useful as intermediate endpoint in trials. CALERIE (Belsky 2023) showed caloric restriction slowed DunedinPACE measurably.

What both share

DNA methylation derived (450K or EPIC arrays).
Both are research-grade; consumer versions (TruDiagnostic, others) generally license one or both.
Both have substantial test-retest variability that should be considered when interpreting changes.
Both require careful interpretation: single timepoints are noisier than trend over multiple time points.

Which to choose

Single screening / risk assessment: GrimAge (or PhenoAge).
Intervention tracking over 6–24 months: DunedinPACE.
Best practice: get both if you can; they answer different questions.

Practical caveat

Consumer epigenetic-age tests claim large age reductions from short interventions. Most of these reported reductions fall within measurement noise. Interpret single-timepoint changes cautiously; look at trends across 12+ months.