Salivary cortisol test: how saliva, urine and hair tests compare with blood

A salivary cortisol test measures cortisol in a small saliva sample. It is one of four ways cortisol is measured. Blood, saliva, urine and hair each show something different, and they are used for different questions. Picking the wrong one can mean a number that doesn’t answer what you asked.

This page compares them: what each measures, what it is used for and where the evidence is thin. It does not interpret any result. Tests for too much cortisol belong with a clinician.

Cortisol

One blood draw for one cortisol result. It can’t diagnose or rule out an adrenal condition by itself.

$109

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Price checked November 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.

Which sample answers which question

Sample	What it measures	Used for	Main limits
Blood	Mostly total cortisol at one moment	A morning level, or a morning and later pair	Changes with the carrier protein; one point in time
Saliva	Free cortisol at one moment	Late-night screening for Cushing’s; daily pattern	Contamination; false positives; needs exact timing
24-hour urine	Free cortisol passed over a day	Screening for Cushing’s	Collection errors; fluid, kidney and method effects
Hair	Cortisol laid down in the hair shaft	Research	No standard collection or range

MedlinePlus says cortisol is mostly in blood but some passes into urine and saliva, and that measuring those fluids is also an accurate way to estimate how much cortisol is in the blood. It adds that a clinician may order more than one type of test. For blood, see the cortisol test guide and AM and PM timing.

Salivary cortisol test

Saliva holds only the free form of cortisol, the part not attached to a carrier protein (Int J Mol Sci, 2025). That has two effects. The numbers are far lower than in blood, and the result isn’t thrown off by changes in that carrier protein, such as those caused by estrogen (Endocrine Reviews, 2024). Saliva is easy to collect at home, but contamination from blood in the mouth can affect the result.

Late-night salivary cortisol test

NIDDK lists a late-night salivary cortisol test as one of the tests for Cushing’s syndrome. Cortisol normally drops just after a person falls asleep. In Cushing’s syndrome it doesn’t. You can collect the sample at home and return it or send it to a lab.

• Timing. Guidelines name midnight, though a laboratory review says samples at 10 p.m. and 11 p.m. have also performed well. It also says two consecutive collections are recommended, though some experts think one is enough (Diagnostics, 2023).
• Who it suits. A 2020 commentary says people with abnormal sleep-wake cycles shouldn’t have it (J Endocr Soc, 2020). A 2026 review lists smoking and tobacco use as causes of false positives and says it is less sensitive for mild cases (J Clin Endocrinol Metab, 2026). Age, high blood pressure and diabetes may raise midnight salivary cortisol, and saliva reference intervals may not suit everyone (Diagnostics, 2023).

Can a saliva test show high cortisol?

It can flag a high level, but a flag is not a diagnosis. In a study of 1,453 late-night saliva samples from 705 patients with suspected Cushing’s syndrome, most patients with at least one elevated result did not have it, so a single elevated level had poor specificity (J Endocr Soc, 2020, via PubMed). NIDDK says no one test is perfect, so doctors usually do two tests. If a result worries you, take it to a clinician and don’t interpret it alone.

Four-point and multi-sample saliva profiles

MedlinePlus says you may be asked to collect a few saliva samples at different times because cortisol changes through the day. The number and times depend on the kit or the lab. The sources used for this page don’t define a standard four-point schedule, so treat any such profile as the seller’s design. A 2024 paper says salivary cortisol profiles sold for “adrenal fatigue” have never been scientifically validated (J Endocr Soc, 2024). See adrenal fatigue.

For how to collect a sample and what a home kit can and can’t show, see at-home cortisol tests.

24-hour urine cortisol test

For a 24-hour urine test, MedlinePlus says you collect all your urine for a day in a special container, starting after you empty your bladder and note the time, and keep it cool. NIDDK lists the 24-hour urinary free cortisol test among the tests for Cushing’s syndrome. MedlinePlus says in some cases a single morning urine sample is used instead.

Points from the reviews:

• Two collections. Day-to-day variation is high, so at least two 24-hour collections are recommended (J Clin Endocrinol Metab, 2026).
• What can skew it. A laboratory review lists high fluid intake, salt intake and kidney function. It also says the result can look normal in mild or on-and-off Cushing’s syndrome, and that over- or under-collection is a risk (Diagnostics, 2023). The 2026 review adds sex, body mass index and age to the list.
• Method. Immunoassays can over-measure urinary cortisol, so cut-offs depend on the method (Diagnostics, 2023).

Don’t stop any medicine before a collection unless your prescriber says to.

Hair cortisol test

Cortisol builds up in hair as it grows. The part nearest the scalp reflects roughly the past month, at about 1 cm of growth a month (Int J Mol Sci, 2025; Front Psychiatry, 2023). It needs no needle, and a 2023 review notes it is less open to short-term effects such as stress at the moment of a blood draw (Front Psychiatry, 2023).

The evidence is the thin part:

• Not routine clinical practice. A 2023 laboratory review says hair is yet to be widely used because there are no standard collection and storage methods, no reference materials and no accepted reference intervals. It adds that hair cortisol may miss mild Cushing’s syndrome (Diagnostics, 2023).
• No standard range. One 2026 study of 256 healthy adults in Northern Italy, using mass spectrometry, reports a reference interval of 0.84 to 8.07 pg/mg. The authors describe it as a benchmark for research. The study found only weak links with body mass index and perceived stress (J Endocrinol Invest, 2026).
• Still a research field. A 2023 review of hair cortisol in studies of psychological treatments calls it little established (Front Psychiatry, 2023).

So a hair cortisol test is not a validated test for adrenal disease, and it can’t tell you whether your stress is “too high”. Don’t use one to decide anything about a medicine.

Dried-urine hormone profiles (DUTCH-style tests)

Some mail-in tests dry several urine samples on filter paper and send them to a lab to measure hormones and their breakdown products. The DUTCH test is one. See our page on the DUTCH test.

One published check of the method, a 2021 paper by staff of the company that makes the test, compared dried and liquid urine, and four dried spot samples against a 24-hour collection, for reproductive hormones and organic acids. It did not test whether the method identifies adrenal disease (BMC Chemistry, 2021). That doesn’t mean the test is poor. It means this page cites no independent evidence on adrenal questions.

Where blood fits

Blood is still the sample used for a morning level and for a morning and later pair, and the tests sold through this site’s price boxes are lab blood draws. Saliva and 24-hour urine collections for Cushing’s screening are arranged by a clinician, who also reads the result. If you take a steroid medicine, don’t stop or change it because of any test. Ask your prescriber. If you are very unwell, with severe weakness, repeated vomiting or fainting, call 911 or go to urgent care.

For published ranges for each sample, see normal cortisol levels. For the tests doctors use when cortisol may be too high, see testing for high cortisol.