1. In both males and females, the majority of circulating testosterone is biologically inactive (60-70%) and bound to protein SHBG. The remaining testosterone circulates weakly bound to other proteins, primarily albumin (30-40%), and as free (not bound to protein) testosterone (<3%). Albumin-bound and free testosterone, together, are frequently referred to as the biologically active or bioavailable testosterone (test code AG03). Testosterone is used for diagnosis of conditions causing increased or decreased levels, and, more commonly, nowadays for hormone replacement therapy.
2. For individuals under 18 years old, please call lab for reference values characterized by tanner stages.
3. Falsely increased results may be seen in patients on high doses of biotin (i.e. > 5mg/day). Samples should only be collected from these patients at least 8 hours following the last biotin administration so as to avoid potential interference.
20-49 yr