This tool provides an estimate of the levels of unbound testosterone in the bloodstream. It is derived from the ratio of total testosterone to sex hormone-binding globulin (SHBG). For instance, a total testosterone level of 500 ng/dL and an SHBG level of 50 nmol/L would yield a specific value, indicating the proportion of testosterone not bound to SHBG and therefore biologically available.
The calculation is a valuable screening method in the assessment of androgen status, particularly in conditions where SHBG levels are abnormal. This has significant benefits in the diagnosis and management of hormonal imbalances affecting both men and women. Historically, direct measurement of free testosterone was complex and costly, making this estimation method a practical alternative for initial evaluation.
