Free Androgen Index (FAI)
The Free Androgen Index is calculated from total testosterone and SHBG and estimates the proportion of biologically available testosterone. It is particularly useful in women to evaluate hirsutism, acne, and polycystic ovary syndrome, where an elevated FAI reflects functional androgen excess. In men it is a secondary measure when SHBG levels are abnormal.
Optimal range: who says what
No institution or named practitioner we track states an optimal target for Free Androgen Index (FAI). How we verify ranges.
- No stated targetNo separate optimal establishedInterpret together with total testosterone and SHBG rather than in isolation
- Lab reference intervalMen: 14.8-94.8, Women: 0.8-11.0What a lab report flags against. A lab interval is not an optimal target.
2 providers include this
Additional Specialized Tests
Why Free Androgen Index (FAI) matters
Indicates bioavailable testosterone. Useful in women with PCOS or hirsutism. Better reflects androgen status than total testosterone alone.
Which Providers Test Free Androgen Index (FAI)?
Superpower is both the cheapest ($349/year) and the most comprehensive (100+ biomarkers) panel that includes Free Androgen Index (FAI).
2 panels that include it, cheapest first
| Provider | Annual Cost | Total Biomarkers | $/Biomarker |
|---|---|---|---|
 Superpower | $349 | 100+ | $3.49 |
| $996 | 59 | $16.88 |
$/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 Free Androgen Index (FAI)
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 · Hims Labs · Healthspan · Vitality Blueprint Standard · Vitality Blueprint Elite · 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 Free Androgen Index (FAI). 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 Free Androgen Index (FAI)?
No separate optimal established: Interpret together with total testosterone and SHBG rather than in isolation. Lab reference interval: Men: 14.8-94.8, Women: 0.8-11.0. That is what a lab report flags against, not an optimal target.
Which blood test providers include Free Androgen Index (FAI)?
2 of the 21 blood testing panels we itemize marker by marker include Free Androgen Index (FAI) 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 Aug 26, 2026 · First published Sep 30, 2025