Biomarker Encyclopedia · hormones · Sutton Coldfield

Free Androgen Index

Also known as: FAI

The free androgen index is a calculated value that estimates the proportion of testosterone not bound to carrier proteins. At The Vesey Private Hospital in Sutton Coldfield, Free Androgen Index is available within 11 private blood test panels, with clinician-reviewed results. This page is educational and does not replace personalised medical advice.

What Free Androgen Index measures

The free androgen index is a calculated value that estimates the proportion of testosterone not bound to carrier proteins. It combines total testosterone with SHBG to indicate the more readily available hormone.

Why it is tested

It is used alongside total testosterone and SHBG to give a fuller picture of androgen status. Several hormone-focused panels report it automatically.

Tests that include Free Androgen Index at The Vesey

Guide prices are read from the current Vesey catalogue and confirmed at booking.

Testosterone Monitoring

Guide price from £148

Hormone Profile

Guide price from £156

Fertility Panel

Guide price from £210

Fertility Panel + STI Screen

Guide price from £220

5 further Vesey panels include Free Androgen Index. See all blood test panels →

Frequently asked questions

How is the free androgen index worked out?

It is calculated from total testosterone and sex hormone binding globulin (SHBG), rather than measured directly. This is why those markers are usually reported together.

Reviewed by Dr Greg Spencer · General Practitioner · Last reviewed 2026-07-07

This page is for general education and information only. It is not medical advice, a diagnosis, or a recommendation for any specific test or treatment, and it does not include reference ranges, which are laboratory-dependent and interpreted by a clinician. Guide prices are indicative and confirmed at the time of booking. Always discuss your health and any test results with a qualified clinician. In an emergency call 999; for urgent non-emergency advice call NHS 111.

Private blood testing in Sutton Coldfield

Clinician-reviewed results. No GP referral needed.

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