Quick Facts
- Sample: Saliva
- Fasting: No fasting required
- Turn-around: 5–7 business days after lab receipt. May take longer based on weather, holiday, or lab delays.
Benefits
- Non-invasive at-home collection – no needles, no office visits, just simple saliva samples
- Maps your daily stress rhythm – four time points reveal how your cortisol rises and falls
- Identifies hidden adrenal issues – catches patterns standard single blood tests often miss
- Supports personalized action plans – gives you and your provider data to target fatigue and sleep
- Affordable, direct access – transparent pricing with detailed results delivered confidentially
- Track progress over time – repeat testing monitors response to stress management or treatment changes
Who Is This Test For?
- Individuals experiencing chronic fatigue, burnout, or low energy despite adequate rest
- People with persistent sleep disturbances or difficulty waking refreshed in the morning
- Anyone suspecting adrenal dysfunction or imbalanced stress-hormone levels
- Those managing long-term glucocorticoid therapy (oral, inhaled, or topical steroids)
- Health-conscious consumers seeking proactive HPA axis monitoring for wellness optimization
- Patients working with providers to evaluate stress-management interventions or lifestyle changes
How It Works – Just 3 Steps
- Collect four saliva samples at home – on waking, before lunch, before dinner, and at bedtime on the same day
- Ship your kit back – complete the forms, refrigerate samples per instructions, and send via overnight mail Monday–Thursday
- Review your results online – receive detailed results with your cortisol curve plotted against reference ranges in 5–7 days
FAQ
What does this test measure? Free salivary cortisol at four points across one day, creating a diurnal curve that reveals your body's stress-hormone rhythm.
Is saliva as accurate as blood? Studies show salivary cortisol explains over 70% of serum cortisol variance and achieves approximately 90.7% sensitivity and 94.1% specificity for adrenal insufficiency (NIH/PMC 2023).
Do I need to fast or avoid medications? No fasting required. Avoid eating, drinking (except water), brushing teeth, or tobacco 30 minutes before each sample; discuss steroid medications with your provider.
What if my results are abnormal? Consistently high, low, or flattened cortisol curves warrant follow-up with a healthcare provider or endocrinologist for confirmatory serum testing or ACTH stimulation.
Can I retest to track changes? Yes—repeat testing is ideal for monitoring response to stress interventions, glucocorticoid tapering, or lifestyle modifications over time.
How soon will I get my report? Results are typically available 5–7 business days after the laboratory receives your specimen.
More Details
What is the purpose of this test?
The 4-Point Cortisol test evaluates your hypothalamic-pituitary-adrenal (HPA) axis by measuring free cortisol in saliva at four time points during one day. Cortisol is your body's primary stress hormone and follows a natural diurnal rhythm—normally highest upon waking and declining toward bedtime (Walk-In Lab). Plotting these four results creates a cortisol curve that reveals patterns of adrenal over-activity, under-activity, or dysregulation linked to fatigue, sleep problems, and metabolic or mood disturbances.
Who would benefit from this test?
Anyone experiencing chronic stress symptoms, persistent fatigue, difficulty managing daily stressors, or non-restorative sleep may benefit. It is particularly valuable for individuals with suspected adrenal dysfunction, those on long-term glucocorticoid therapy (oral, inhaled, or topical), and people seeking preventive insights into their stress-hormone balance. A 2024 study found that undiagnosed glucocorticoid-induced adrenal insufficiency contributed to death in 3.7–15.7% of septic glucocorticoid users, highlighting the importance of early detection (NIH/PMC 2024).
When should I order this test?
Consider ordering if you have persistent stress-related symptoms, unexplained low energy, insomnia, or difficulty recovering from illness. It is also appropriate if you and your clinician want to monitor adrenal function during or after glucocorticoid therapy, or if you are implementing stress-management programs and wish to track physiological changes over time (Walk-In Lab).
How do I interpret the results?
Your report displays cortisol values at each collection time alongside reference ranges and typically graphs them as a diurnal curve. A normal pattern shows elevated morning cortisol with gradual decline throughout the day. Abnormal patterns may include:
Consistently high:
- What it means: Possible hypercortisolism or chronic stress activation
- Typical action: Discuss stress reduction strategies; rule out Cushing’s syndrome if levels are severe
Consistently low:
- What it means: Possible adrenal hypo-function or insufficiency
- Typical action: Consider confirmatory ACTH stimulation testing; refer to endocrinology
Flattened curve:
- What it means: HPA axis dysregulation with loss of normal cortisol rhythm
- Typical action: Evaluate stress load and sleep hygiene; monitor with repeat testing
Reversed rhythm:
- What it means: Abnormal circadian pattern with elevated evening cortisol
- Typical action: Assess for sleep disorders or shift work; implement lifestyle interventions
Interpretation should always integrate your symptoms, medications, and medical history—isolated results do not diagnose disease.
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.
Pre-test preparation
Collect your four samples on the same day at the specified times: upon waking (before getting out of bed), before lunch, before dinner, and at bedtime. Avoid eating, drinking anything except water, brushing your teeth, or using tobacco for 30 minutes before each collection to prevent contamination. Discuss oral, inhaled, or topical steroids with your provider beforehand, as they can suppress cortisol levels (ZRT Lab). No fasting is required.
How often should I get tested?
- Initial screening for adrenal dysfunction: Once, then retest if results are abnormal or symptoms persist
- Monitoring stress-management interventions: Every 3–6 months during active treatment or lifestyle changes
- Glucocorticoid tapering or discontinuation: As directed by provider; often every 1–3 months until HPA recovery is confirmed
- Long-term glucocorticoid users (asymptomatic): Annually, or sooner if new fatigue, weakness, or hypotension develops
Why early detection matters
Unrecognized adrenal insufficiency can lead to adrenal crisis—a life-threatening condition with severe hypotension, shock, and metabolic derangement. Adrenal crisis incidence is approximately 3.6–8.3 episodes per 100 patient-years in known adrenal insufficiency, but rises to about 15.1 per 100 patient-years in glucocorticoid-induced cases (NIH/PMC 2024). Early identification of abnormal cortisol patterns allows timely intervention—stress-dose steroid education, medical alert identification, and appropriate endocrine follow-up—reducing morbidity and potentially preventing premature death in at-risk individuals.
Related tests you may consider
Cortisol AM – gold-standard evaluation of adrenal function; complements diurnal saliva testing.
DHEA-S – assesses adrenal androgen production alongside cortisol for broader HPA axis characterization
Thyroid #3 Extreme Blood Test Panel – thyroid disorders mimic or worsen fatigue and metabolic symptoms; useful for complete endocrine assessment
