Cortisol PM · low result
What does a low Cortisol PM mean?
Short answer
A low late-afternoon or evening cortisol is usually normal — that is when cortisol is supposed to be lowest — so a low PM value on its own rarely means anything. It becomes relevant only alongside a low morning cortisol (adrenal insufficiency), in someone taking steroid medication that suppresses their own production, or in a night-shift worker whose peak has moved. The morning value, and an ACTH stimulation test if needed, are what answer the adrenal question.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When does this result need same-day care?
- Low cortisol with vomiting, confusion, very low blood pressure or severe weakness — emergency care (possible adrenal crisis)
What is the normal range for Cortisol PM?
- age 18+, drawn 4–6 PM: 2.30 – 11.9 mcg/dL
Full reference table, citations and testing options: Cortisol PM biomarker page.
What are the common causes of low Cortisol PM?
- Normal circadian low point
- Corticosteroid medication (prednisone, inhaled or topical steroids, injections) suppressing the adrenal axis
- Adrenal insufficiency (primary or from pituitary disease) — only if the morning value is also low
- Shift work (rhythm shifted)
- Hypothyroidism, opioids (mild)
What symptoms go with low Cortisol PM?
- None when it's a normal evening low
- Fatigue, weight loss, dizziness on standing, nausea and salt craving with true insufficiency
What do clinicians usually check next?
- Morning (7–9 am) cortisol on a rested day; ACTH stimulation test if that is also low
- Review all steroid-containing medications
- Sodium, potassium, glucose, TSH
Follow-up tests available at TestWell: TSH (Thyroid Stimulating Hormone) ($26.99), TSH + Free T4 ($27.99), Glucose ($14.99), Cortisol ($32.99).
How do you recheck Cortisol PM?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Men's Hormone Panel | Panel · 7 tests | $199.99 | No | 3–5 business days |
| Metabolism & Weight Loss Panel | Panel · 8 tests | $119.99 | Yes | 2–5 business days |
| Fitness & Performance Panel | Panel · 8 tests | $119.99 | Yes | 2–5 business days |
| Cortisol (AM) | Test | $26.99 | No | 2–4 business days |
Common questions
Does a low evening cortisol mean adrenal fatigue?
'Adrenal fatigue' is not a recognized diagnosis, and a low evening value is the expected rhythm. Real adrenal insufficiency shows a low morning cortisol and a failed stimulation test.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.