Does "free cortisol" mean cortisol the body is not using?Updated 3 hours ago
No, the reverse. Free cortisol is the active fraction; the protein-bound pool is the reserve. The cortisol found in urine is a small overflow from the active pool, and its quantity reflects how much active cortisol was circulating. The cortisol the body has used and inactivated leaves mostly as metabolites, which this wand does not measure.