IGF-1 Z-Score
The IGF-1 Z-score expresses IGF-1 as standard deviations from the age- and sex-specific mean, which is useful because IGF-1 declines steeply with age. A score near zero is average for age, while values near +2 or -2 suggest growth hormone excess or deficiency, respectively. It helps avoid misclassifying normal age-related changes as disease.
Optimal range: who says what
Institutions, researchers and practitioners draw the line in different places. Each position is listed with who holds it and, where a document states it, a link. How we verify ranges.
- Institution or study-1.0 to +1.0Near the age-adjusted mean; both extremes carry the J-curve risk seen for absolute IGF-1Same U-shaped mortality curve as absolute IGF-1: the 10th and 90th percentiles both fare worse than the median
- Lab reference interval-2.0 to +2.0 (normal range)What a lab report flags against. A lab interval is not an optimal target.
2 providers include this
Advanced / Specialty Markers
Why IGF-1 Z-Score matters
Compares IGF-1 to age-matched population. More meaningful than absolute IGF-1 value. Helps identify growth hormone deficiency or excess relative to peers.
Which Providers Test IGF-1 Z-Score?
Cheapest: Hims Labs at $349/year. Most comprehensive: Vitality Blueprint Elite, 138 biomarkers for $700/year.
2 panels that include it, cheapest first
| Provider | Annual Cost | Total Biomarkers | $/Biomarker |
|---|---|---|---|
| $349 | 75+ | $4.65 | |
| $700 | 138 | $5.07 |
$/Biomarker is annual cost divided by the panel's advertised biomarker count, not the price of this one test. We track 23 blood test providers (32 plans); 21 of those plans are itemized marker by marker. Compare all of them.
19 itemized panels do not include IGF-1 Z-Score
Superpower · WHOOP Advanced Labs · Labcorp OnDemand · Life Extension Elite · Everlywell · Mito Health · InsideTracker · Function Health · Marek Health Base · Marek Health Comprehensive · Marek Health Complete · Marek Health Executive · Blueprint · Empirical Health · Oura Health Panels · SiPhox Health · Healthspan · Vitality Blueprint Standard · Ultrahuman Blood Vision Annual
11 providers not itemized in our matrix
We have not itemized these marker by marker (some sell tests one at a time), so this page cannot say whether they offer IGF-1 Z-Score. Check with them directly.
Life Extension Standard · Quest Health · Ultrahuman Blood Vision · Lifeforce · Hundred Health · Personalabs · Walk-In Lab · HealthLabs · WHOOP Specialized Panels · Marek Health Essential · Vitality Blueprint Upload
Frequently Asked Questions
What is the optimal range for IGF-1 Z-Score?
Published position: -1.0 to +1.0 (Near the age-adjusted mean; both extremes carry the J-curve risk seen for absolute IGF-1). Lab reference interval: -2.0 to +2.0 (normal range). That is what a lab report flags against, not an optimal target.
Which blood test providers include IGF-1 Z-Score?
2 of the 21 blood testing panels we itemize marker by marker include IGF-1 Z-Score in their panels. This biomarker has limited availability.
Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed Sep 3, 2026 · First published Nov 30, 2025