Reference range
Reference ranges vary by lab, age and sex. Your own lab report carries the authoritative range, and your clinician reads it with you.
Why it matters
Free testosterone is the fraction available to bind androgen receptors and produce a biological effect. Two members can share an identical total testosterone value yet present with very different free testosterone — typically because their SHBG is markedly different. In a REVRCEL hormone protocol, free testosterone is the marker that most often correlates with how a member feels.
How REVRCEL clinicians read it
Free testosterone is typically calculated from total testosterone + SHBG + albumin (the Vermeulen equation) or measured directly. Direct equilibrium dialysis is the gold standard.
Included in
- Hormone Optimization Panel
Common questions
What is free testosterone?
The fraction of testosterone in serum that is not bound to SHBG or albumin and is therefore available to bind androgen receptors.
Why does my free testosterone matter more than total?
Because the bound fraction is not biologically active. Free testosterone tracks closer to symptoms in most members.
Related biomarkers
Statements have not been evaluated by the FDA. This page is educational and is not medical advice.
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