Cortisol, P.M. Test
A Cortisol, P.M. test measures cortisol, the main adrenal stress hormone, from a sample collected later in the day. Because cortisol follows a daily rhythm, this evening timing is chosen on purpose so a clinician can read the result in the right context.
About this test
Cortisol is made by the adrenal glands, small glands that sit above the kidneys, and it helps the body respond to stress while supporting energy, blood sugar, and blood pressure. Cortisol rises and falls across the day in a natural rhythm, generally running higher earlier and easing later on.
The test is done with a simple blood draw at a patient service center. A phlebotomist collects a sample from a vein, usually in the arm, and the sample goes to the laboratory.
Who might consider this test?
- Because the P.
- timing is chosen deliberately, this test is usually part of a clinician-guided evaluation rather than a routine self-check.
Test details
| Quest code | 4213 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
Related tests and panels
Quest resources
Additional details
What this test looks at
This test measures cortisol at a set point later in the day. Cortisol sits at the end of a feedback loop that runs from the brain to the adrenal glands, and the amount circulating shifts through the day. By fixing the collection time to the evening, the test captures cortisol at a consistent part of its rhythm, which makes the result more meaningful when a clinician compares it with a morning sample.
It helps to remember what a single timed result is and is not. It describes how much cortisol is present at that moment in the day; it does not, by itself, label the cause of a symptom or confirm the popular term "adrenal fatigue," which is not a recognized medical diagnosis.
Why the daily rhythm matters here
The value of an evening cortisol result often comes from comparison. Cortisol naturally eases later in the day, so an evening sample gives a clinician a second point in the rhythm to consider alongside a morning one. Seeing how the hormone changes from one part of the day to another can carry more meaning than either sample taken alone, which is why timing is so central to cortisol testing.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
Why is this cortisol test done in the evening?
Cortisol follows a daily rhythm and generally eases later in the day. Collecting the sample in the evening captures a different point in that rhythm, which a clinician can compare with a morning sample to see how the hormone changes.
What does an evening cortisol test measure?
It measures the level of cortisol, the main adrenal stress hormone, in a blood sample taken later in the day. Cortisol comes from the adrenal glands above the kidneys and reflects part of the body's stress-hormone system.
Should I order this with a morning cortisol test?
Many people do, because the change from morning to evening is often more informative than a single value. A clinician can guide whether pairing the two makes sense for your situation.
Do I need to time my visit carefully?
Yes. Because cortisol changes across the day, plan to have the sample collected at the time your test or clinician specifies. Following that timing helps make the result meaningful.
Can this test diagnose adrenal fatigue?
No. Adrenal fatigue is a popular term but not a recognized medical diagnosis, and no test confirms it. A cortisol result describes how the hormone is behaving, which a clinician interprets alongside symptoms and history.
What does a Cortisol P.M. test cost without insurance?
$39. Celio Health's price is a flat cash price and insurance is never billed: the required physician's order is included.