Our Methodology

Health Age (PhenoAge)

Your Health Age is calculated using the PhenoAge model developed by Dr. Morgan Levine and colleagues at Yale University, published in 2018 in the journal Aging. PhenoAge is one of the most widely cited biological age models in longevity research, validated on the NHANES dataset of adults aged 20–84.

Unlike calendar age, which only measures time since birth, PhenoAge estimates how old your body appears to be based on patterns in nine blood biomarkers. Research has shown that PhenoAge is a stronger predictor of mortality risk, disease onset, and healthspan than calendar age alone.

The Nine Markers

PhenoAge uses the following nine biomarkers. All values must be present for a full PhenoAge calculation. If fewer than four are available, we show a heuristic estimate instead.

• Albumin — a protein made by the liver; reflects nutritional status and liver function
• Creatinine — a waste product filtered by the kidneys; reflects kidney function
• Glucose (fasting) — blood sugar level; reflects metabolic health
• C-Reactive Protein (CRP) — an inflammation marker; elevated levels are associated with accelerated aging
• Lymphocyte percentage — a type of white blood cell; reflects immune function
• Mean Corpuscular Volume (MCV) — average size of red blood cells; reflects anemia and nutritional status
• Red Cell Distribution Width (RDW) — variation in red blood cell size; associated with inflammation and aging
• Alkaline Phosphatase (ALP) — an enzyme reflecting liver and bone health
• White Blood Cell count (WBC) — total immune cell count; reflects immune activity and inflammation

The Formula

PhenoAge is calculated in two steps:

• Step 1 — Linear combination: Each marker value is multiplied by a published coefficient and summed with a constant: xb = −9.73 + Σ(coefficient × marker value)
• Step 2 — Mortality score conversion: The linear score is converted to a mortality score, then mapped to a biological age in years using the Gompertz mortality model.

Unit conversions are applied before calculation: Albumin g/dL → g/L (×10), Creatinine mg/dL → µmol/L (×88.4), Glucose mg/dL → mmol/L (÷18), CRP mg/L → mg/dL (÷10) then natural log.

The formula and coefficients are published in: Levine ME et al., An epigenetic biomarker of aging for lifespan and healthspan, Aging (Albany NY), 2018.

Important Limitations

• PhenoAge was validated on adults aged 20–84. We do not calculate it for panels collected when you were under 18.
• PhenoAge uses your age at the time of blood collection, not your current age.
• A single PhenoAge reading is less meaningful than a trend across multiple panels over time.
• PhenoAge is a research estimate, not a clinical measurement. It should not be used for medical decision-making without consulting a physician.
• If fewer than 4 of the 9 markers are present, we show a heuristic estimate labelled accordingly.

Health Score

Your Health Score (0–100) is a composite score calculated across your blood markers, grouped into health domains. It is not based on published research — it is a proprietary scoring system designed to give you an at-a-glance sense of how your results compare to standard reference ranges.

How it works

• Each marker is scored based on how far it falls within or outside its reference range
• Markers are grouped into health domains: Metabolic, Cardiovascular, Immune, Liver, Kidney, Nutritional, Hormonal, and others
• Each domain receives a score based on the markers present in that domain
• The overall score is a weighted composite across all domains

Score bands

• 85–100 Excellent — most markers within range, no significant flags
• 70–84 Good — majority of markers within range, minor flags present
• 50–69 Fair — several markers outside range or trending in concerning direction
• Below 50 Needs Attention — multiple markers flagged, consider discussing with your doctor

The Health Score is a wellness tracking tool, not a medical assessment. A high score does not mean you are healthy, and a low score does not mean you are sick. Always interpret your score alongside your doctor's clinical judgment.

References

Levine ME, Lu AT, Quach A, et al. An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY). 2018;10(4):573-591. doi:10.18632/aging.101414

Questions

If you have questions about our methodology, contact us at privacy@myvitalsync.app.