Cortisol, 15-Minute Free Serum Concentration (Post-CRH Stimulation)
This test measures your cortisol levels in blood after you receive a small dose of corticotropin-releasing hormone (CRH). It helps doctors check how well your body responds to stress and whether your pituitary gland is making enough cortisol.
Assesses pituitary-adrenal function with a stress response test.
Key facts at a glance
- LOINC
- 48101-0
- Short code
- Cortis 15M pre 1 ug/kg CRH IV SerPl-sCnc
- Synonyms
- Cortis 15M pre 1 ug/kg CRH IV SerPl-sCnc
- Category
- hormone
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86701
- 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
Your doctor may order this test if they suspect conditions like Cushing’s syndrome, adrenal insufficiency, or pituitary disorders. It’s often part of a larger evaluation to confirm or rule out hormonal imbalances that affect stress responses or metabolism.
How the Test Works
You’ll receive an injection of CRH, a hormone that stimulates cortisol production. Blood is drawn 15 minutes later to measure your cortisol levels. This helps evaluate how effectively your body produces cortisol in response to stress.
What to Expect Before the Test
No special preparation is needed, but inform your doctor about any medications (especially steroids) or recent illnesses that might affect results. Avoid caffeine or alcohol before testing as they can influence cortisol levels.
What to Expect During the Test
You’ll have a small needle inserted into your arm for blood collection. The process is quick and usually painless. You may feel a slight pinch, but most people tolerate it well. The blood sample is then sent to a lab for analysis.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low cortisol levels after CRH stimulation may indicate adrenal insufficiency or pituitary dysfunction, while high levels could suggest overproduction of cortisol (e.g., Cushing’s syndrome) or resistance to its effects. This test helps differentiate between these conditions and guides treatment decisions.
Short name
Cortisol after CRH test
Frequently asked questions
How long does it take to get results?
What does a normal result mean?
Can I take my usual medications before 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