Biomarker Reference · Free T
Free Testosterone (Free T) is a clinical biomarker used in male-hormones assessment. Free testosterone is the unbound fraction that diffuses freely into cells and exerts direct androgenic and anabolic effects. It is measured in 2 laboratory tests on BiomarkersLabs.com.
Free testosterone is the unbound fraction that diffuses freely into cells and exerts direct androgenic and anabolic effects. It represents only 1–2% of total circulating testosterone but is the biologically active pool. Free testosterone rises and falls with total testosterone but is also influenced independently by SHBG concentration — when SHBG increases, free testosterone falls even if total remains stable, and vice versa.
Free testosterone is the best single biochemical marker of androgen bioactivity and is particularly valuable when SHBG is abnormal or when total testosterone is borderline but symptoms are present. Direct free testosterone immunoassays are widely available but less accurate than equilibrium dialysis or calculated free testosterone; practitioners should know which method their laboratory employs. Free testosterone is used to diagnose hypogonadism, to monitor testosterone replacement therapy, and to investigate androgen excess in women.
Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.
2 tests on BiomarkersLabs.com include this biomarker.
Free Testosterone reference range in this test: Approximately 5–21 pg/mL in adult men; method- and age-dependent.
Free Testosterone reference range in this test: Approximately 5.0–21.0 pg/mL (17–73 pmol/L) in adult men; 0.0–4.2 pg/mL (0–15 pmol/L) in adult women. Assay- and age-specific.
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