The Longevity Hierarchy That Actually Matters

The practical version, before the mechanisms

1 min read·Updated July 2026

If you want the practical version before the underlying science, this is it. Everything here is explained and cited properly in the sections that follow.

TierWhat's in itEvidence strength
Tier 1 — Do thisVO2 max training, resistance training, blood pressure control, not smoking, consistent sleep, healthy body compositionStrong — large cohort and trial evidence, covered in depth in the Exercise, Heart & Metabolic Health, and Sleep guides
Tier 2 — Reasonable, well-studiedCaloric restriction principles, time-restricted eating, a Mediterranean-style dietModerate-strong — genuine human trial data, covered in Sections 5–6
Tier 3 — Emerging, incomplete evidenceNAD+ precursors (NMN/NR), metformin, rapamycinMechanistically plausible, backed by animal or observational data; human longevity outcomes remain unproven
Tier 4 — Proceed with real cautionUnregulated peptides (BPC-157, TB-500) and similar compoundsLittle to no robust human trial data; physician guidance essential if used at all

The bottom line

No supplement or intervention compensates for smoking, chronic sleep deprivation, sedentary behaviour, obesity, or chronic unmanaged stress. Get Tier 1 right first — the exotic interventions in Tiers 3 and 4 sit at the margin, not a substitute for the fundamentals.