A cortisol test measures your body’s stress hormone and its daily rhythm.
It detects cortisol in blood, saliva, or urine.
Morning serum cortisol often ranges 6–23 µg/dL, giving a clear snapshot of peak levels.
What is a cortisol test
A cortisol test tracks the hormone your adrenal glands release in response to stress. Clinicians use it to check if your cortisol levels follow a normal daily pattern or if they stay too high or too low.
Saliva cortisol test kits collect several samples across the day to map the cortisol curve. A single blood draw gives a snapshot useful for an AM cortisol test. A 24-hour urine collection sums total cortisol output for a full-day view.
Saliva testing fits at-home monitoring best. It’s noninvasive and captures free cortisol that mirrors active hormone. Many labs accept four-point saliva panels that show the wake peak and the evening drop under 5 µg/dL, which helps spot abnormal rhythms.
Choose a multi-point saliva kit if you want rhythm data. Choose a serum cortisol test for a clinical morning check. If results look abnormal, contact your clinician for follow-up testing and interpretation.
Types of cortisol tests available
Saliva cortisol test
The saliva cortisol test best tracks daily cortisol rhythms. It measures free cortisol in saliva, which mirrors blood free cortisol with correlations near r=0.8 (J Clin Endocrinol, 2017).
You collect 2–4 samples across the day. Labs commonly use AM, midday, evening, and late-night points to map the diurnal curve. Multiple samples reveal morning peaks and evening drops better than a single blood snapshot.
Saliva testing gives the best balance of convenience and accuracy for home stress monitoring. Take this next step: follow timing exactly and skip food, coffee, smoking, and brushing teeth for 30 minutes before sampling.
Serum cortisol test
Serum cortisol test gives an accurate morning snapshot. It uses blood drawn in a clinic or capillary blood from a finger-prick kit.
Venous samples measure cortisol in µg/dL. Typical 8 AM ranges run about 6–23 µg/dL, so labs compare your value to that window.
A serum reading works well when you want a single, reliable baseline. A morning serum cortisol test best captures peak adrenal output for screening.
Finger-prick kits send capillary blood to a CLIA lab and return results in 2–5 days. For example, some providers report cortisol plus DHEA from one drop of blood with fast digital results.
Collect between 7 and 9 AM while fasting and rested for consistent comparison to reference ranges. If your value falls outside the lab range, consult your clinician for follow-up testing or referral.
24-hour urine cortisol test
The 24-hour urine cortisol test measures total daily cortisol output. It’s the preferred method when you need to see how much cortisol your body clears over a full day.
The lab reports results in micrograms per 24 hours. Typical reference ranges run about 10–100 µg/24 h, varying by assay and lab.
Clinicians use this test to diagnose adrenal disorders such as Cushing’s or Addison’s. You collect every urine void for 24 hours in a provided container, keep it cool, and return it to the lab. Missed samples invalidate the result; follow kit timing exactly.
A full-day collection shows total cortisol output better than one-time blood draws. Refrigerated storage cuts sample degradation significantly in most trials.
Ask your clinician for a 24-hour urine cortisol test or order a validated at-home urine collection kit to test cortisol levels.
Diurnal cortisol test
A diurnal cortisol test uses four to six samples from wake to bedtime. It maps your cortisol rhythm and shows morning peaks and evening drops.
Mapping highs and lows beats single-sample checks. It reveals patterns a single AM cortisol test misses.
Use a saliva cortisol test kit for ease at home. Collect samples at wake, 30 minutes later, mid-afternoon (about 3 pm), and at bedtime.
Follow kit timing. Avoid heavy exercise and caffeine before sampling. Ship samples to the lab per instructions. Results often return in 3–7 days. Bring the report to your clinician.
If you want clarity, order a home cortisol test. Track a cortisol rhythm test to guide next steps.
Can I test cortisol levels at home
You can test cortisol at home reliably. Home kits measure cortisol in saliva, blood, or urine and send samples to a CLIA lab for processing.
A saliva cortisol test asks for 2–4 samples across a day to map your cortisol rhythm. A finger-prick at-home cortisol testing kit gives a morning snapshot and returns results in 2–5 days. Saliva kits often report results in 5–7 days. Many kits cost between $86 and $99 and include prepaid shipping and physician review.
Kits work like this: order online, collect samples with clear timing rules, seal the kit, then mail it with the included label. Saliva tests offer the best mix of convenience and rhythm tracking because they let you test morning and evening levels without a clinic visit. If you need total daily output, choose a 24-hour urine kit and follow its full collection steps.
Pick a kit that matches your goal, follow the timing exactly, and ship the sample same day. If results fall outside normal cortisol levels, contact your clinician for confirmatory lab testing and next steps. Order a CLIA-processed kit and follow the instructions for accurate results.
Best at-home cortisol test kits in 2026
LetsGetChecked Cortisol Test
The LetsGetChecked Cortisol Test is a blood sample test using a finger‑prick sample and measures serum cortisol.
The kit costs $99 and returns results with a 2-5 day turnaround. It earns top reliability ratings; the kit comes with a physician review included.
The review helps interpret borderline cortisol values and guides next steps. The sample process uses a finger‑prick lancet and prepaid shipping.
Lab returns a digital report showing cortisol level and physician notes. It suits anyone who wants a quick serum cortisol test without a clinic visit.
If you seek diurnal rhythm data, choose a saliva or 24‑hour urine test instead.
RxHomeTest Cortisol AM/PM or 24-Hour Test
The RxHomeTest AM/PM kit tracks cortisol rhythm effectively. The product uses a saliva-based kit and asks for 2-4 samples across 24 hours.
Results return in 5-7 days. This design suits diurnal cortisol testing and maps morning peaks and evening drops. Many users report clear patterns that help guide sleep, stress, and medication timing.
Choose two samples for AM/PM checks or four for full 24-hour coverage. Multi-point saliva sampling reveals cortisol rhythm clearly.
The test fits a home cortisol workflow. It includes simple collection, prepaid shipping, and CLIA lab processing. Need to map morning and full-day cortisol? Order this test.
It delivers actionable data your clinician can use. It’s ideal for tracking full-day stress patterns and your cortisol rhythm. Use it to monitor treatment response across weeks.
myLAB Box Adrenal Stress Test
myLAB Box offers fast adrenal checks. It uses a finger-prick blood sample to measure cortisol and DHEA.
Results arrive in 2-5 days, one of the fastest for a home cortisol test. Healthline scores it 3.8 out of 5.
This kit fits people who need a rapid serum cortisol test. Collection is easy and shipping is fast. Use this quick assessment cortisol test kit when you want prompt cortisol levels feedback.
Collect a morning sample for AM cortisol test accuracy.
HRT.org Cortisol Saliva Test
HRT.org offers affordable saliva cortisol testing. The kit starts at $86 and returns results in 5–7 days.
The lab uses CLIA-certified lab processing and sends digital results you can access quickly. The test measures cortisol from saliva and works well as a saliva cortisol test for tracking daily rhythm. Use 2–4 samples across the day for a clear diurnal cortisol test picture.
This kit fits people who want a practical home cortisol test without high cost. You get lab-grade analysis and a quick turnaround. Order the HRT.org kit if you need an inexpensive, reliable cortisol saliva test kit to monitor your cortisol levels at home.
How to perform a cortisol test at home
You can reliably test cortisol at home. Collect samples with strict timing, clean technique, and correct shipping to get accurate results.
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Prepare: avoid food, drink, smoking, vigorous exercise, and toothpaste for 30 minutes before collection.
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Saliva sampling: use the provided tube or swab. Collect within 5 minutes of waking, 30 minutes after waking, mid-afternoon (around 4 pm), and at bedtime. Aim for about 1 mL per tube. Label each tube with time and date.
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Finger‑prick blood: warm your hand, clean the finger, use the lancet, collect 2–4 drops or fill the card per kit instructions. Best time for a serum cortisol test is morning between 8–9 am, fasting if the kit asks.
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Handle samples: follow kit notes—some saliva tubes need freezing, others ship at room temperature. Use the biohazard bag and absorbent pad in the kit.
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Ship smart: use the prepaid mailer. Drop off early in the week to avoid weekend delays. If cold packs are included, pack them right before shipping.
Following these exact steps cuts common lab errors. Timing can change cortisol results by up to 30% (J Clin Endocrinol 2019). If you want a simple option, choose a saliva cortisol test kit with four samples. Mail the kit same business day and check results with your clinician for next steps.
What is the best time to test cortisol
A morning cortisol test gives the most reliable baseline. Cortisol rises sharply after waking—the cortisol awakening response increases levels by about 50% within 30 minutes.
For a serum cortisol test, schedule a blood draw between 7 AM and 9 AM. Labs use an 8 AM standard and report morning values near 6–23 µg/dL (LabCorp reference).
We recommend a saliva cortisol test at waking and again 30 minutes later to capture the peak. Collect extra samples at noon and at bedtime for a diurnal cortisol test that maps your daily rhythm.
Use a late-night salivary cortisol sample around 11 PM to confirm low evening levels and to screen for excess cortisol. This late sample helps detect abnormal suppression seen in some conditions.
Choose a 24-hour urine cortisol test when you need total daily output. Start by discarding the initial morning urine and collect all urine for the next 24 hours to measure overall cortisol production.
Timing matters more than the test type for accurate results. If you test at home, follow the kit’s timing and prep steps and note your wake time on the form. Which test fits your schedule best? Rule of thumb: morning for a snapshot, multiple points for rhythm, 24-hour for total output.
Are saliva cortisol tests accurate
Saliva cortisol tests are reliable for tracking daily cortisol rhythms. They measure free cortisol, the fraction that reaches tissues, and they correlate with serum free cortisol up to 0.9 in clinical studies (J Clin Endocrinol 2019). A single saliva sample gives a valid snapshot for that moment.
We favor saliva for at-home stress monitoring because it lets you collect multiple points across the day. A typical saliva cortisol test kit asks for 2–4 samples. That sampling captures the morning peak and evening fall of the diurnal cortisol rhythm, which a single blood draw can’t map.
Serum cortisol tests give a total cortisol value bound to carrier proteins. They work well for a focused morning cortisol test in clinic. A blood sample suits suspected adrenal failure or urgent care needs. A home cortisol test using saliva gives better data for daily stress patterns than a lone serum reading.
Saliva limits come from user error and some medicines that change saliva flow or cortisol binding. Severe disorders need 24-hour urine or ACTH stimulation tests for diagnosis. For screening and routine tracking, saliva testing gives practical, repeatable data with low cost and fast sampling.
Saliva tests shine for personal stress mapping because they’re simple and evidence-backed. Order a saliva cortisol test kit and collect AM and PM samples over two days to map your rhythm.
Normal cortisol levels by time of day
Cortisol peaks in the morning and drops by evening. Your body follows this natural rhythm to manage energy and stress.
Morning cortisol peak usually falls between 6 and 23 µg/dL on a serum cortisol test at 8 AM (165–635 nmol/L). A standard AM cortisol test captures this peak. Labs report afternoon serum values near 3–10 µg/dL (83–276 nmol/L). Late-night serum cortisol typically sits under 1.8 µg/dL (<50 nmol/L).
Saliva cortisol test ranges differ from blood values. Waking saliva commonly reads about 5–25 nmol/L. Evening saliva often falls to 1–4 nmol/L. Late-night salivary cortisol used for Cushing screening usually reads under 1 nmol/L on most assays. Matching the test type to its reference range prevents wrong conclusions.
|
Time of Day |
Serum Cortisol (µg/dL) |
Saliva Cortisol (nmol/L) |
|---|---|---|
|
Morning (8 AM) |
6–23 |
5–25 |
|
Afternoon |
3–10 |
2–8 |
|
Late Night |
<1.8 |
<1 |
24-hour urine cortisol measures total daily output. Normal urinary free cortisol runs below 50 µg per 24 hours on many lab reports. A diurnal cortisol test that samples multiple times documents the rhythm more clearly than a single snapshot.
Compare your result to the range tied to your test type and collection time. If your value sits outside the listed ranges, bring the result to your clinician for next steps.
Factors that affect cortisol testing accuracy
Preparation and daily habits strongly alter cortisol test accuracy. Medications, exercise, sleep, acute stress, and sample handling each shift results. Oral steroids raise serum cortisol for days. Vigorous exercise can spike cortisol for up to 60 minutes after activity.
We tell patients to follow clear prep steps. For an AM cortisol draw, aim for a blood draw between 7 and 9 am after an 8-hour fast. For saliva samples, avoid food, drink, smoking, and toothbrushing 30 minutes before collection. Acute stress skews values and can change immune markers; read more about stress and white blood cell count.
A saliva cortisol test tracks diurnal rhythm well, but contamination from food or blood lowers accuracy. A serum cortisol test gives a reliable morning snapshot when you fast. For a 24-hour urine cortisol, collect every void and refrigerate samples. Stop biotin supplements and high-dose steroids before testing when your clinician permits. Avoid caffeine for 12 hours and alcohol for 24 hours to reduce transient spikes.
Repeating a surprising result is wise. If results conflict with symptoms, repeat the test under strict prep. Follow sample timing, skip interfering substances, and contact your clinician for abnormal readings.
How to interpret your cortisol test results
Abnormal cortisol results require prompt follow-up. High readings often point to prolonged stress, Cushing’s syndrome, or steroid exposure, while low readings suggest adrenal insufficiency or pituitary dysfunction.
A morning serum cortisol or a multiple-sample saliva cortisol test gives the clearest picture. Lifestyle steps plus targeted supplements can help—see our guide on ashwagandha for anxiety relief.
See a clinician if you have severe symptoms such as dizziness, unexplained weight loss or gain, persistent fatigue, muscle weakness, or new high blood pressure. A morning cortisol below 3 µg/dL often indicates adrenal insufficiency; persistent AM levels above your lab’s reference range warrant further workup.
Your provider may order an ACTH stimulation test, a dexamethasone suppression test, or a 24-hour urine cortisol to confirm diagnosis. Confirm abnormal home results with lab testing within two weeks and bring a complete medication list to your appointment.
Specialized cortisol tests for diagnosis
ACTH stimulation test
The ACTH stimulation test is the standard test to diagnose adrenal insufficiency and Addison’s disease. Clinician measures a baseline cortisol, injects 250 µg cosyntropin (synthetic ACTH), measures cortisol at 30 and 60 minutes.
A normal response shows a peak cortisol above 18–20 µg/dL (500–550 nmol/L) or an increase near 7 µg/dL on those samples. Failure to mount that rise points to primary or secondary adrenal failure and directs further endocrine workup.
We recommend performing the test in a clinic to ensure correct timing and handling of samples. Cosyntropin testing gives clear diagnostic value when labs follow strict protocols.
If you suspect low cortisol, ask your clinician about the ACTH stimulation test and bring prior labs for comparison.
Dexamethasone suppression test
This test diagnoses Cushing’s syndrome by checking cortisol suppression. It uses a synthetic steroid to see if your cortisol production falls normally.
You take 1 mg dexamethasone at 11 p.m. and measure serum cortisol at 8 a.m.
Abnormal results mean cortisol fails to suppress after dexamethasone. That finding suggests autonomous cortisol secretion from an adrenal or pituitary source.
The low-dose dexamethasone approach balances simplicity and clinical value. It avoids complex sampling and fits routine labs. If your morning cortisol stays high, ask your clinician for imaging and endocrine evaluation.
Clinicians often pair this test with a late-night salivary cortisol for clarity. Talk to your doctor about ordering the overnight test. Report unexplained weight gain, bruising, or persistent fatigue.
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Late-night salivary cortisol test
We recommend testing cortisol at bedtime to screen for Cushing’s. Bedtime levels should sit near their daily low, so a high value raises concern.
The late-night salivary cortisol test uses saliva collected at sleep time. Studies report about 90% sensitivity and 85% specificity in detecting Cushing’s (meta-analysis).
Collect with a clean tube, avoid food, exercise, and nicotine for 30 minutes before sampling. If you have a pituitary tumor, review foods to avoid with pituitary tumor for related care.
This test fits home screening when clinics are far and symptoms persist. Get an at-home salivary cortisol kit and mail samples to a certified lab for definitive results.
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How often should you test cortisol levels
Test cortisol based on symptoms and your monitoring goals. Track only as often as results will change care.
If you have new signs like unexplained fatigue, weight gain, or high blood pressure, get a test promptly. Order a morning AM cortisol test or a multi-point saliva cortisol test. A single serum cortisol at 8–9 am gives a snapshot. A 24-hour urine cortisol captures total daily output.
When you start or change treatment, test more often. Measure every 4–6 weeks during dose adjustment. Repeat every three months once values stabilize. Use the same test type each time for valid comparisons.
For stress mapping, use a diurnal cortisol test. Collect 3–4 saliva samples across the day for two days to map your cortisol rhythm. That method shows morning peaks and evening lows and reveals dysregulation better than a single blood draw.
Routine testing without a clear reason wastes money and time. Target tests to symptoms, meds, or specific diagnostic questions. If you suspect Cushing’s or Addison’s, your clinician will direct specialized testing like ACTH stimulation or dexamethasone suppression.
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Educational notice: This content is provided for informational and educational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional for medical concerns.
