What is the reference range for Night Cortisol (Saliva)?

The standard reference range for Night Cortisol (Saliva) is Collection-time-specific; night (around 23:00–24:00 before sleep) approximately <0.4 ng/mL.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Which tests measure Night Cortisol (Saliva)?

Night Cortisol (Saliva) is measured in 2 tests on BiomarkersLabs.com, including Adrenocortex Stress Profile (ASP), Comprehensive Adrenal Function Profile.

Biomarker Reference · Cortisol-NT

What does the Night Cortisol (Saliva) test measure?

Q: What is Night Cortisol (Saliva)?

Late-evening or bedtime cortisol is the lowest point of the circadian cycle. Measurement of free cortisol in saliva at this time is recommended by endocrine guidelines as a screening tool for hypercortisolism.

Q: Why is Night Cortisol (Saliva) measured?

An elevated late-night salivary cortisol is one of the most sensitive screening tests for Cushing syndrome and also flags loss of circadian rhythm in chronic stress and psychiatric illness. A flat curve with little difference between morning and night values is a hallmark of dysregulated HPA function.

Q: Which tests measure Night Cortisol (Saliva)?

Night Cortisol (Saliva) is measured in 2 tests on BiomarkersLabs.com, including Adrenocortex Stress Profile (ASP), Comprehensive Adrenal Function Profile.

Night Cortisol (Saliva) (Cortisol-NT) is a clinical biomarker used in adrenal-stress assessment. Late-evening or bedtime cortisol is the lowest point of the circadian cycle. It is measured in 2 laboratory tests on BiomarkersLabs.com.

Reference Range: Collection-time-specific; night (around 23:00–24:00 before sleep) approximately <0.4 ng/mL.
Units: nmol/L, ng/mL, µg/dL
Measured In: 2 tests
Category: Adrenal

Functional medicine optimalA clear nadir, with values well below the evening level; collection-time-specific and method-dependent.

What is Night Cortisol (Saliva)?

Late-evening or bedtime cortisol is the lowest point of the circadian cycle. Measurement of free cortisol in saliva at this time is recommended by endocrine guidelines as a screening tool for hypercortisolism.

Why is Night Cortisol (Saliva) measured?

An elevated late-night salivary cortisol is one of the most sensitive screening tests for Cushing syndrome and also flags loss of circadian rhythm in chronic stress and psychiatric illness. A flat curve with little difference between morning and night values is a hallmark of dysregulated HPA function.

Reference ranges

Standard reference: Collection-time-specific; night (around 23:00–24:00 before sleep) approximately <0.4 ng/mL.
Functional medicine optimal: A clear nadir, with values well below the evening level; collection-time-specific and method-dependent.
Units: nmol/L, ng/mL, µg/dL

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

Tests that measure Night Cortisol (Saliva)

2 tests on BiomarkersLabs.com include this biomarker.

BML-ADR-003Comprehensive

Adrenocortex Stress Profile (ASP)

Night Cortisol (Saliva) reference range in this test: Collection-time-specific; night (around 23:00–24:00 before sleep) approximately <0.4 ng/mL.

BML-ADR-028Comprehensive

Comprehensive Adrenal Function Profile

Night Cortisol (Saliva) reference range in this test: Approximately <1.0 ng/mL (<2.8 nmol/L) before sleep; method-specific.

Related clinical conditions

Related Biomarkers

Frequently measured alongside

Morning Cortisol (Saliva)Cortisol-AM2 tests Evening Cortisol (Saliva)Cortisol-PM2 tests Dehydroepiandrosterone (Saliva)DHEA2 tests Midday Cortisol (Saliva)Cortisol-MD1 test Cortisol-to-DHEA Ratio (derived)Cortisol:DHEA3 tests Noon Cortisol (Saliva)Noon Cortisol1 test Cortisol Awakening ResponseCAR6 tests Diurnal Cortisol Slope (Derived)Cortisol Slope3 tests

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