Cortisol, Salivary, Free, 24-Hour Composite (Mass Concentration)
This test measures the total amount of free cortisol your body releases into your saliva over a 24-hour period. It helps assess cortisol levels, which are important for managing stress, sleep, and other bodily functions.
["This test helps diagnose conditions related to abnormal cortisol production, such as Cushing’s syndrome or adrenal insufficiency."]
Key facts at a glance
- LOINC
- 51489-3
- Short code
- Cortis sp7 p chal Sal-mCnc
- Synonyms
- Cortis sp7 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 Matters
Cortisol is a hormone produced by your adrenal glands that plays a key role in how your body responds to stress, regulates metabolism, and supports immune function. Chronic stress or certain medical conditions can lead to either too much or too little cortisol. Measuring salivary cortisol over 24 hours provides a more accurate picture than single-point measurements, as it reflects natural daily fluctuations.
How the Test Works
During this test, you’ll collect saliva samples at regular intervals over a full day. Each sample is analyzed to measure free cortisol levels. The results are then combined to give an average concentration over the 24-hour period. This method avoids the variability that can occur with blood tests, which may be affected by time of day or stress at the time of collection.
What to Expect Before the Test
No special preparation is needed for this test. You’ll be given instructions on how to collect saliva samples at home, typically using a cotton swab or similar device. Make sure to follow the instructions carefully to ensure accurate results. Avoid smoking, chewing gum, or eating/drinking immediately before collecting samples.
What to Expect During the Test
The test involves collecting saliva samples throughout the day. You’ll likely receive a kit with instructions and a logbook to record when each sample is taken. Most people complete this at home, but some may need to visit a healthcare provider for guidance. The process is simple and painless.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Salivary cortisol testing is particularly useful for diagnosing conditions like Cushing’s syndrome (excess cortisol) or adrenal insufficiency (low cortisol). It can also help identify whether cortisol levels are consistently high or low, which may indicate underlying hormonal imbalances. Unlike blood cortisol tests, which can be influenced by stress or timing, salivary cortisol provides a more reliable measure of baseline hormone levels.
Frequently asked questions
What does a high or low salivary cortisol result mean?
How often will I need this test?
Can I take medications before or after this test?
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