Guide
Longevity blood tests and biomarkers: a grounded guide
8 min read · last reviewed 22 August 2026
You do not need a boutique longevity panel to see the markers that matter. Most of the values with real mortality evidence behind them appear on ordinary blood tests your GP has ordered for years. What the longevity industry adds is mostly packaging — and occasionally useful convenience.
The markers with the strongest ageing evidence
The PhenoAge model is a useful shortlist precisely because its nine inputs were selected by how strongly they predicted mortality in population data: albumin, creatinine, fasting glucose, C-reactive protein, lymphocyte percentage, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count — plus age itself.
Each is individually mundane. Glucose tracks metabolic health; CRP tracks inflammation; albumin falls with illness and frailty; the blood-count indices shift with marrow and nutritional health. Their power is collective: together they sketch how much physiological strain a body is carrying.
Markers worth knowing that panels oversell
Beyond the basics, a handful of measures have solid outcome literature in the right context — lipids including ApoB for cardiovascular risk, HbA1c for glucose over time, blood pressure most of all. The oversold end includes one-off hormone snapshots, sprawling micronutrient panels in people without symptoms, and any single measurement treated as a verdict rather than a data point. Biology is noisy; trends across repeat measurements beat snapshots.
Testing without being sold to
Three principles keep testing useful. First, test with a purpose: a marker is worth measuring if some realistic result would change what you do. Second, interpret with a clinician, especially anything abnormal — reference ranges and context matter more than a dashboard's colour coding. Third, be wary when the company selling the test also sells the fix; that loop is where surrogate markers get dressed up as outcomes.