Cortisol in Saliva (Free Cortisol)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of free cortisol, a form of the stress hormone cortisol, found naturally in your saliva. It helps assess your body’s cortisol levels over time without blood draws.

Quick summary

["This test helps evaluate your body’s stress response and adrenal function by tracking cortisol levels in saliva."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC: 51490-1
Short code: Cortis sp5 p chal Sal-mCnc
Synonyms: Cortis sp5 p chal Sal-mCnc
Category: hormone
Sample: serum
Container: Red-top tube (SST)
Units: N/A
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
Specimen volume: 5 mL
Stability: Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 4–24 hours
Order: routine

Why This Test Is Done

Doctors may order a free cortisol saliva test to diagnose conditions related to cortisol imbalance, such as Cushing’s syndrome (too much cortisol) or adrenal insufficiency (too little cortisol). It can also help monitor stress levels or rule out hormonal disorders like pituitary issues.

How the Test Works

You’ll collect saliva samples over a specified period (often 24 hours or multiple times daily). Each sample is placed in a provided container, and the lab analyzes the cortisol content using immunoassay (a sensitive detection method).

What to Expect Before the Test

No special preparation is needed, but avoid smoking, caffeine, or eating/drinking immediately before collecting samples. Stressful activities or medications (like steroids) may affect results, so discuss these with your provider.

What the Results Mean

Results are compared to reference ranges for free cortisol in saliva, which can vary by lab. Elevated levels may indicate overactive adrenal glands or Cushing’s syndrome, while low levels could signal adrenal fatigue or other hormonal imbalances.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Free Cortisol

Frequently asked questions

What does cortisol do in the body?

Cortisol is a steroid hormone produced by your adrenal glands. It helps regulate metabolism, immune response, and stress reactions. Chronic stress or certain medical conditions can disrupt normal cortisol production, leading to symptoms like fatigue, weight changes, or mood swings.

How often should I get this test?

The frequency depends on your symptoms and medical needs. Your doctor may recommend this test periodically if you have a history of hormonal disorders, stress-related conditions, or if you’re taking medications that affect cortisol levels.

Can diet or lifestyle affect cortisol levels?

Yes. Diet high in sugar or processed foods, poor sleep, and chronic stress can temporarily raise cortisol. Avoiding these factors before testing helps ensure accurate results. Always follow your provider’s instructions for optimal sample collection.

Sources

1
MedlinePlus — Laboratory TestsSource
2
Lab Tests OnlineSource
3
Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy