Quick Facts
- Sample: Blood draw (8–9 AM)
- Fasting: Not required
- Turn-around: 1-2 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Early detection of adrenal disorders reduces hospitalization risk by up to 25% (AACE 2024)
- No fasting needed—simple morning blood draw fits easily into your routine
- Fast results in 24–48 hours delivered directly to your secure online account
- Confidential & convenient—order online with local lab collection
- Measures peak cortisol when hormone levels naturally surge for accurate adrenal assessment
- Cost-effective screening avoiding expensive stimulation tests in many cases
Who Is This Test For?
- Chronic fatigue sufferers experiencing unexplained tiredness despite rest
- Stress-conscious individuals monitoring cortisol as part of wellness routines
- Those with weight changes including unexplained weight gain or loss
- People with muscle weakness or suspected adrenal insufficiency
- Cushing's syndrome suspects showing signs of excess cortisol (bruising, facial puffiness)
- Anyone seeking baseline adrenal health screening before symptoms develop
How It Works – Just 3 Steps
- Order online — Order your test and schedule a blood draw appointment between 8–9 AM
- Visit lab — Quick blood draw via single venipuncture into a standard serum tube; samples ship promptly per lab protocol
- Review results — Result available within 24–48 hours to help provide guidance for next steps
FAQ
What is cortisol and why does timing matter? Cortisol is a steroid hormone from your adrenal glands that regulates stress response, immunity, and metabolism. It peaks naturally around 8–9 AM, so morning testing captures your body's natural peak for accurate adrenal assessment.
What do the results mean? Normal morning cortisol ranges from approximately 140–690 nmol/L (5–25 mcg/dL). Low levels suggest adrenal insufficiency; high levels indicate excess cortisol production. Your provider will interpret results in clinical context.
Can medications affect my test? Yes—corticosteroids, oral contraceptives, and certain medications can impact cortisol levels. Always disclose current medications to your provider before testing.
What if my results are abnormal? Consult an endocrinologist for further evaluation. Abnormal results may warrant confirmatory tests like ACTH stimulation or dexamethasone suppression testing.
Do I need to fast before this test? No fasting is required. Simply arrive between 8–9 AM for optimal cortisol measurement.
Why is early morning the only time to test? Cortisol follows a strict daily rhythm, peaking in early morning and declining throughout the day. Testing outside this window significantly reduces diagnostic accuracy.
More Details
What is the purpose of this test?
The Cortisol Blood Test, AM measures cortisol concentration in your morning blood sample to evaluate adrenal gland function (Mayo Clinic 2025). Cortisol is essential to immune function, nervous system regulation, and metabolism. By testing when cortisol naturally peaks, this test helps screen for and diagnose adrenal disorders including Addison's disease (insufficient cortisol), Cushing's syndrome (excess cortisol), and Cushing's disease (ACTH-driven overproduction).
Who would benefit from this test?
You may benefit from this test if you experience chronic fatigue, unexplained weight changes, muscle weakness, or signs of hormone imbalance (Cleveland Clinic 2025). It's also valuable if you have a family history of adrenal disorders, experience persistent stress-related symptoms, or are monitoring a known adrenal condition. Health-conscious individuals seeking preventive adrenal screening find this test particularly useful for baseline assessment.
When should I order this test?
Order this test if symptoms suggest abnormal cortisol levels or if your provider recommends adrenal screening. Ideal timing is between 8:00 and 9:00 AM when cortisol peaks naturally. Schedule your blood draw within this window for maximum diagnostic accuracy. You may also order this alongside the ACTH Blood Test to comprehensively assess adrenal function.
How do I interpret the results?
140–690 nmol/L (5–25 mcg/dL):
- What it means: Normal adrenal function
- Typical action: Continue routine screening as recommended
< 140 nmol/L (< 5 mcg/dL):
- What it means: Low—suggests adrenal insufficiency
- Typical action: Consult endocrinologist; may need ACTH stimulation test
> 690 nmol/L (> 25 mcg/dL):
- What it means: High—suggests excess cortisol
- Typical action: Consult endocrinologist; may need dexamethasone suppression test
A morning cortisol level ≥ 332 nmol/L demonstrates high specificity for normal adrenal reserve, often avoiding the need for further stimulation testing (Therapeutic Advances in Endocrinology 2025).
Pre-test preparation
No fasting is required. Collect your sample between 8:00 and 9:00 AM for optimal cortisol measurement. If possible, minimize stress before testing and avoid strenuous exercise the morning of your appointment, as physical stress can temporarily elevate cortisol. Disclose all current medications, supplements, and recent oral contraceptive use to your provider, as these may affect results.
How often should I get tested?
- Routine health screening: Every 1–2 years or as recommended by provider
- Monitoring known adrenal disorder: Every 3–6 months or per treatment plan
- Evaluating new symptoms: Single test; repeat if symptoms persist
- Post-treatment follow-up: As directed by endocrinologist
Why early detection matters
Early identification of cortisol imbalances enables timely intervention and prevents serious complications (AACE 2024). Undiagnosed adrenal insufficiency can escalate to life-threatening adrenal crises; early detection reduces related hospitalizations by up to 25%. Detecting excess cortisol early helps prevent bone loss, cardiovascular disease, and metabolic complications. Proactive screening supports personalized wellness and prevents disease progression.
Related tests you may consider
Cortisol Blood Test, PM — measures cortisol levels in the afternoon to check adrenal gland function and diagnose conditions related to hormone levels.
Cortisol Urine Test, Urinary Free, 24-Hour — collects all urine over 24 hours to measure the amount of unbound (free) cortisol your body produces throughout the day, helping evaluate conditions related to cortisol excess or deficiency.
Adrenocorticotropic Hormone (ACTH) Blood Test —measures ACTH levels to determine if cortisol abnormalities stem from pituitary or adrenal origin
