What does the Testosterone, Total test measure?

Why is Testosterone, Total measured?

Total testosterone is the cornerstone of hypogonadism diagnosis in males and the first-line androgen marker in females with suspected hyperandrogenism. In men a low morning total testosterone triggers further investigation — repeat confirmatory testing, measurement of LH and FSH to classify primary versus secondary hypogonadism, and consideration of free or bioavailable testosterone when SHBG is abnormal. In women elevated total testosterone suggests polycystic ovary syndrome, non-classic congenital adrenal hyperplasia, or androgen-secreting neoplasms. Because total testosterone includes protein-bound fractions, alterations in SHBG — due to obesity, ageing, thyroid disease, or oestrogen — can shift the total value without changing free hormone, so clinical context and ancillary tests are essential to interpretation.

Reference ranges

Standard reference

Adult males: ~264–916 ng/dL (9.2–31.8 nmol/L); adult females: ~8–60 ng/dL (0.3–2.1 nmol/L) # REVIEWER FLAG: Reference intervals are strongly sex- and age-dependent and assay-specific — reviewer to confirm against Quest's LC-MS/MS harmonised ranges.

Functional medicine optimal

Many endocrinology sources consider a morning total testosterone below 300 ng/dL (10.4 nmol/L) on two occasions supportive of hypogonadism when symptoms are present; values between 200–400 ng/dL (7–14 nmol/L) fall into a grey zone where free or bioavailable testosterone adds clarity.

Units

ng/dL, nmol/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.