Cortisol in Saliva (Free Cortisol, 24-Hour Average)
This test measures the amount of cortisol, a natural steroid hormone, in your saliva over 24 hours. It helps assess your body’s cortisol levels, which are important for managing stress, sleep, and other bodily functions.
["This test helps doctors check if your cortisol levels are normal or if they’re too high or too low, which can affect stress responses and health."]
Key facts at a glance
- LOINC
- 58641-2
- Short code
- Cortis sp11 p chal Sal-sCnc
- Synonyms
- Cortis sp11 p chal Sal-sCnc
- 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
Saliva cortisol testing is often used to diagnose conditions like Cushing’s syndrome (too much cortisol) or adrenal insufficiency (too little cortisol). Unlike blood tests, saliva cortisol measures free cortisol, which is more accurate for long-term stress assessment. Your doctor may recommend this test if they suspect hormonal imbalances related to stress or sleep disorders.
How the Test Works
You’ll collect saliva samples throughout the day, typically in small tubes, and return them to the lab. The lab analyzes the total cortisol content in your saliva over 24 hours to get an average reading. This method avoids fluctuations from blood cortisol levels that can spike or drop quickly.
Sample Collection and Preparation
You’ll receive instructions on how to collect saliva samples at home, usually by spitting into a tube at set times (e.g., every 2–4 hours). Follow the instructions carefully to ensure accurate results. Avoid eating, drinking, or smoking for 30 minutes before collecting samples to minimize interference.
What to Expect Before the Test
No special preparation is needed beyond following the collection instructions. If you’re on medications that affect cortisol (like steroids), let your doctor know, as this may impact results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Saliva cortisol testing is particularly useful for detecting chronic stress-related cortisol imbalances, which may not show up clearly in single blood tests. High cortisol levels can cause weight gain, fatigue, high blood pressure, or mood changes, while low levels may indicate adrenal fatigue, poor stress response, or other hormonal issues. This test helps diagnose conditions like adrenal insufficiency, Cushing’s syndrome, or pituitary disorders.
Frequently asked questions
How long does it take to get the results?
Can I eat or drink anything before collecting saliva samples?
Will this test show if I have diabetes?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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