Which tests measure Cortisol?

Cortisol is measured in 1 test on BiomarkersLabs.com, including Blood Spot LCMS Hormones 7 with SHBG and Thyroids.

Biomarker Reference · F

What does the Cortisol test measure?

Q: What is the reference range for Cortisol?

The standard reference range for Cortisol is Morning 5–25 ng/mL; afternoon/evening lower. Single time-point dried blood spot cortisol is less informative than diurnal salivary profiles but can serve as a snapshot.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Cortisol (F) is a clinical biomarker used in thyroid-endocrine assessment. Cortisol is the principal glucocorticoid, synthesised in the adrenal zona fasciculata under ACTH drive and subject to pronounced diurnal variation with a morning peak. It is measured in 1 laboratory test on BiomarkersLabs.com.

Reference Range: Morning 5–25 ng/mL; afternoon/evening lower. Single time-point dried blood spot cortisol is less informative than diurnal salivary profiles but can serve as a snapshot.
Units: ng/mL, nmol/L
Measured In: 1 test
Category: Thyroid

Functional medicine optimalFunctional practitioners interpret morning dried blood spot cortisol within the mid-range of the reference interval as reflecting balanced HPA axis tone, though this framework is not diagnostically validated.

What is Cortisol?

Cortisol is the principal glucocorticoid, synthesised in the adrenal zona fasciculata under ACTH drive and subject to pronounced diurnal variation with a morning peak. Blood spot cortisol represents total circulating hormone; because cortisol-binding globulin is not captured by the collection method the relationship to serum total and free cortisol is complex and method-dependent.

Why is Cortisol measured?

Cortisol assessment underpins the diagnosis of Cushing syndrome, adrenal insufficiency, and stress-related dysregulation. Single-point dried blood spot cortisol has limited diagnostic power compared to 24-hour urine free cortisol or salivary diurnal curves, but it is used in functional practice to complement multi-point sampling or when venepuncture is impractical.

Reference ranges

Standard reference: Morning 5–25 ng/mL; afternoon/evening lower. Single time-point dried blood spot cortisol is less informative than diurnal salivary profiles but can serve as a snapshot.
Functional medicine optimal: Functional practitioners interpret morning dried blood spot cortisol within the mid-range of the reference interval as reflecting balanced HPA axis tone, though this framework is not diagnostically validated.
Units: ng/mL, nmol/L

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

Tests that measure Cortisol

1 test on BiomarkersLabs.com include this biomarker.

BML-THY-030Comprehensive

Blood Spot LCMS Hormones 7 with SHBG and Thyroids

Cortisol reference range in this test: Morning 5–25 ng/mL; afternoon/evening lower. Single time-point dried blood spot cortisol is less informative than diurnal salivary profiles but can serve as a snapshot.

Related clinical conditions

Related Biomarkers

Frequently measured alongside

Oestradiol (Dried Blood Spot)E22 tests ProgesteroneP41 test TestosteroneT1 test Dehydroepiandrosterone Sulphate (Dried Blood Spot)DHEA-S2 tests Thyroid-Stimulating HormoneTSH5 tests Free ThyroxineFT45 tests Free TriiodothyronineFT35 tests Sex Hormone-Binding Globulin (Dried Blood Spot)SHBG2 tests

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