Choosing a test · 4 min read

Blood Test vs DNA Test for Biological Age

“Blood” describes a sample; “DNA methylation” describes a measurement.

AI-assisted editorial draft · Source check: 6 September 2026 · Independent reviewer: not yet assigned

The categories overlap

A DNA-methylation test can use blood or saliva. A blood-chemistry model uses laboratory values such as glucose or albumin. Asking only whether a test uses blood will not identify its scientific method.

Source 1: TruDiagnosticSource 2: Elysium HealthSource 3: Aging / Levine et al.

Compare the work involved

Read how the sample is collected, who processes it, and what happens if collection fails. If you already have laboratory results, check that every required marker is present and uses the correct units before considering a published calculation.

Choose the measurement, then the sample

A convenient sample is useful only if the resulting measure suits your goal. Do not assume that a more invasive sample produces a more useful score, or that a saliva kit avoids all privacy considerations.

Educational information, not medical advice. This guide is an AI-assisted editorial draft awaiting independent review.
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Sources & verification

  1. TruAge test: product, price and collection

    TruDiagnostic · Accessed 2026-09-06

  2. Index: product and pricing

    Elysium Health · Accessed 2026-09-06

  3. An epigenetic biomarker of aging for lifespan and healthspan (2018)

    Aging / Levine et al. · Accessed 2026-09-06