Quick Facts
- Sample: Saliva (6 collections over 24 hours)
- Fasting: Not required (avoid food/drink 2 hours before collection)
- Turnaround: 3–5 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Identify stress dysregulation early before burnout or depression develops—measure what routine checkups miss.
- No clinic visits, needles, or fasting—collect six samples at home during your normal routine for convenience and accuracy.
- Actionable results with science-backed interventions—abnormal patterns are reversible; results guide targeted lifestyle and treatment approaches.
- Track your progress—repeat testing after 3–6 months to confirm recovery from stress-reduction efforts or treatment response.
Who Is This Test For?
- Persistently fatigued or low-energy individuals despite adequate sleep and exercise
- High-stress professionals & caregivers seeking early detection of burnout or stress dysregulation
- Anyone experiencing mood changes, sleep difficulties, or anxiety without clear medical cause
- People with depression, PTSD, or anxiety monitoring treatment response or disease severity
- Preventive health seekers with family history of mood disorders or stress-related illness
- Post-treatment recovery—individuals verifying cortisol restoration after addressing stress or mental health conditions
How It Works – Just 3 Steps
- Order online & receive kit at home. No physician referral needed. Begin testing during a typical week of normal routine.
- Collect six saliva samples. Three quick morning collections (upon waking, 30 min post-waking, 60 min post-waking), plus midday, evening, and bedtime samples—all via simple passive saliva into labeled tubes.
- Mail kit back in prepaid envelope & review results. Results arrive within 3-5 business days as a detailed report showing your cortisol curve, with reference ranges.
FAQ
What is the cortisol awakening response (CAR)? The CAR measures how much your cortisol—your body's main stress hormone—rises in the first 30–60 minutes after waking. A healthy response involves a ~50% increase within 30 minutes, then progressive decline throughout the day. This pattern reflects how well your hypothalamic-pituitary-adrenal (HPA) axis—your central stress system—is functioning. (ZRT Laboratory, 2022)
What does an abnormal CAR mean? A blunted (flat) CAR may indicate chronic stress, depression, burnout, or PTSD; an elevated CAR may suggest acute anxiety or bipolar disorder. An abnormal CAR is not a diagnosis itself but a biomarker prompting further investigation. Discuss results with your healthcare provider to identify underlying causes and develop a treatment plan. (Cleveland Clinic, 2025; PubMed Central, 2024)
How accurate is saliva cortisol testing? Salivary cortisol achieves 89% diagnostic accuracy, 85% sensitivity, and 90% specificity for HPA axis assessment—comparable to or exceeding blood-based testing. Saliva measures biologically active (free) cortisol available to tissues, whereas blood measures mostly protein-bound cortisol unavailable for cellular action. (Journal of Clinical Endocrinology & Metabolism, 2025)
Can I take medications while testing? Continue all regular medications as prescribed without stopping. Note medications and supplements on your test form; certain drugs (glucocorticoids, some antidepressants, stimulants) influence cortisol and should be considered in result interpretation. Never alter medication dosing without consulting your healthcare provider.
How soon will I see results? Results are delivered within 3–5 business days of lab receipt. You'll receive a detailed report showing your cortisol levels at each collection time, plotted against reference ranges and graphed as your cortisol rhythm curve.
More Details
What is the purpose of this test?
The Cortisol Awakening Response Kit measures your body's cortisol—your primary stress hormone—in the first critical hour after waking. This timeframe captures the most informative and reliable snapshot of your hypothalamic-pituitary-adrenal (HPA) axis function. In healthy individuals, cortisol should rise approximately 50% within 30 minutes of waking, then decline steadily throughout the day. This dynamic pattern reflects how well your central stress-response system responds to the demands of the day ahead. Dysregulated patterns—either blunted (too flat) or exaggerated (too high)—indicate that your HPA axis may be struggling with chronic stress, burnout, mood disorders, or other physiological challenges. (NIH/PubMed Central, 2024; Salimetrics, 2019)
What biomarkers are measured in this test?
- Cortisol (awakening response at 0, 30, and 60 minutes post-waking)
- Cortisol (midday measurement)
- Cortisol (evening measurement)
- Cortisol (bedtime measurement)
- DHEA-S (dehydroepiandrosterone sulfate)
Who would benefit from this test?
This test is ideal for anyone experiencing unexplained fatigue, sleep difficulties, mood changes, or persistent low energy without obvious medical explanation. Healthcare workers, caregivers, and high-stress professionals benefit from early detection of stress dysregulation before burnout develops—approximately 66–82% of U.S. workers report burnout in 2025. Individuals diagnosed with depression, anxiety, or PTSD may use the CAR to monitor treatment response or disease severity; research shows CAR predicts antidepressant efficacy and depression relapse risk. Those with family histories of mood disorders, chronic fatigue, or stress-related illness can use the test for preventive health screening. People exploring links between stress physiology and secondary complaints—weight gain, immune dysfunction, digestive issues, or hormone imbalances—also benefit from objective HPA axis assessment. (Forbes, 2025; Frontiers in Neuroscience, 2022; Cleveland Clinic, 2025)
When should I order this test?
Order this test when establishing a baseline of your stress physiology, when experiencing stress-related symptoms without clear cause, or after lifestyle changes to assess improvement. Repeat testing every 6–12 months as part of preventive health monitoring, or every 3–6 months if you've begun stress-reduction interventions or mental health treatment to verify cortisol pattern recovery. Avoid testing during acute illness, immediately after major life stressors, or during unusual sleep schedules—instead, test during a "typical" week to capture your baseline function. Ensure you maintain your normal sleep schedule for at least 2–3 nights before testing; extreme sleep deprivation artificially lowers cortisol and skews results. (ZRT Laboratory; Salimetrics, 2019)
How do I interpret the results?
Your results show cortisol levels (measured in nmol/L) at each collection time, plotted against reference ranges and displayed as a graph of your daily cortisol curve. Review the interpretation table below and discuss findings with your healthcare provider.
Upon waking
- Normal range: 3.7–9.5 nmol/L
- What it means: Baseline cortisol level
- Typical action: Used for baseline comparison
30 minutes post-waking
- Normal range: 5.3–19.1 nmol/L
- What it means: Peak cortisol awakening response (CAR)
- Typical action: Should show ~50% rise from waking level
60 minutes post-waking
- Normal range: 2.6–12.6 nmol/L
- What it means: Completion of CAR
- Typical action: Should return toward baseline
Midday (11 AM–1 PM)
- Normal range: 1.2–3.0 nmol/L
- What it means: Normal daytime cortisol decline
- Typical action: Progressive decrease
Evening (5 PM–7 PM)
- Normal range: 0.6–1.9 nmol/L
- What it means: Further cortisol decline
- Typical action: Continued decrease
Bedtime
- Normal range: 0.4–1.0 nmol/L
- What it means: Lowest cortisol level
- Typical action: Supports sleep
Interpretation patterns:
Normal CAR — A robust 50%+ rise within 30 minutes, return to baseline by 60 minutes, and progressive decline through the day. This indicates healthy HPA axis responsiveness and resilience.
Blunted CAR (flat or minimal rise, remaining below expected ranges) — Associated with chronic stress, depression, burnout, PTSD, chronic fatigue, or adrenal insufficiency. Your provider may recommend further testing (ACTH stimulation, thyroid function) and lifestyle intervention or treatment.
Elevated/Exaggerated CAR (sharp rise exceeding ranges, sustained into midday) — May indicate acute stress, anxiety, bipolar disorder, or early-stage hyperactive stress response. Warrants investigation of stressors and mental health assessment.
Inverted cortisol rhythm (evening/night samples inappropriately elevated, failing to decline) — Suggests circadian rhythm disruption, shift work stress, or chronic sleep disturbance requiring medical evaluation.
An abnormal CAR is reversible; clinical research shows that stress-reduction interventions, sleep optimization, regular exercise, and mental health support restore normal cortisol patterns within 3–6 months. (Frontiers in Neuroscience, 2022; PubMed Central, 2024)
Pre-test preparation
Timing & sleep: Collect samples during a typical week of normal routine. Maintain your normal sleep schedule for at least 2–3 nights beforehand; aim for 7–9 hours nightly. Extreme sleep deprivation artificially flattens the cortisol curve.
Morning collections (most critical): Collect your first sample within 5 minutes of waking (eyes open), the second exactly 30 minutes post-waking, and the third exactly 60 minutes post-waking. These three collections form the core of the test and require precise timing.
Avoid interfering factors: For all samples, avoid eating, drinking (except plain water), or brushing teeth for 2 hours before collection. Avoid caffeine, nicotine, and stimulants for at least 2 hours before morning samples, as these acutely elevate cortisol.
Medications: Continue all regular medications as prescribed without alteration. Note medications on your test requisition; certain classes (glucocorticoids, some antidepressants, stimulants) can influence results and should be considered in interpretation.
Collection technique: Use passive drool—allow saliva to pool in your mouth, then gently direct it into the labeled tube. Ensure samples are free of bubbles. (ZRT Laboratory; Salimetrics, 2019)
How often should I get tested?
Baseline health assessment
- One-time test, then repeat every 12 months as preventive screening
Active stress-reduction intervention
- Repeat after 3–6 months to verify cortisol recovery
Monitoring depression or anxiety treatment
- Repeat every 3–6 months during treatment
- Then every 6–12 months once stable
Post-burnout recovery
- Repeat at 3 months, 6 months, and 12 months
- to confirm HPA axis restoration
Preventive monitoring (no current symptoms)
- Baseline test
- Then every 12 months or as part of annual wellness screening
Monitoring PTSD or chronic stress recovery
- Repeat every 3–6 months until CAR normalizes
- Then repeat annually
Repeat testing during a typical week at similar times of year (e.g., fall 2025 vs. fall 2026) to minimize seasonal variation in stress physiology. (Cleveland Clinic, 2025; Frontiers in Neuroscience, 2022)
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Why early detection matters
Approximately 66–82% of U.S. workers report burnout in 2025, yet most identify burnout only after exhaustion and cognitive decline set in. The cortisol awakening response can detect HPA axis dysregulation weeks to months before symptoms become noticeable, enabling preventive intervention. Research published in Frontiers in Neuroscience (2022) demonstrates that CAR measured at psychiatric hospital admission independently predicts depression severity and relapse risk post-discharge—making it a clinically meaningful early warning system for mood disorders. Similarly, individuals with PTSD characteristically show a blunted CAR, which serves as an objective biomarker for trauma impact and treatment response. Early detection of cortisol dysregulation empowers you to intervene proactively with stress management, sleep optimization, exercise, nutrition, and professional mental health support—all of which restore normal cortisol patterns within 3–6 months. By the time severe burnout, depression, or chronic fatigue develops, substantial damage to motivation, immune function, and relationships may have occurred. Catching HPA axis dysregulation early prevents this cascade and supports lasting resilience. (Forbes, 2025; Frontiers in Neuroscience, 2022; PubMed Central, 2024)
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