Adrenocorticotropic hormone (ACTH) is produced by the pituitary gland and controls the release of cortisol from the adrenal glands. Testing ACTH levels helps evaluate the entire hypothalamic-pituitary-adrenal (HPA) axis — the system that governs your body’s stress response, energy levels, blood pressure, immune function, and metabolism.
The ACTH blood test is ordered when evaluating:
- Cushing’s syndrome — excess cortisol production causing weight gain, high blood pressure, stretch marks, and fatigue
- Addison’s disease (adrenal insufficiency) — insufficient cortisol causing chronic fatigue, low blood pressure, weight loss, and salt cravings
- Abnormal cortisol results that need further investigation to identify the source (pituitary vs. adrenal vs. external)
- Chronic unexplained fatigue, weakness, or dizziness that may have an adrenal component
- Adrenal tumors (pheochromocytoma or adenoma workup)
⚠️ Important collection note: ACTH levels follow a strong circadian rhythm, peaking in the early morning (6–8 AM) and declining throughout the day. This test must be collected in the morning for accurate results. ACTH also degrades rapidly — Labcorp’s certified phlebotomists handle proper collection and rapid processing to ensure sample integrity.
Physician order included. No insurance or referral required. HSA and FSA eligible. Results in 24–48 hours.
📅 Last Updated: May 2026 | 🩺 Medically Reviewed by: Edward Salko, D.O., Medical Director | 🧪 Lab Partner: Labcorp
Also Known As
Corticotropin, Highly Sensitive ACTH, Serum Adrenocorticotropic Hormone
The Purpose of an ACTH Test
Your body relies on the intricate, delicate balance of the endocrine system to function at its best. This system produces several different hormones, which play varied but important roles in determining your overall health and well-being. Chief among them is adrenocorticotropic hormone (ACTH). It triggers the production of cortisol in the adrenal glands, which in turn does everything from maintaining healthy blood sugar and metabolism to controlling immune system function. ACTH plasma test levels that are elevated or low could signal a number of health issues, such as Addison disease, Cushing’s syndrome, or an adrenal gland tumor, among others. And because cortisol is a stress hormone, your levels can influence your mental health as well as your physical wellness.
What Does the ACTH Lab Test Measure?
ACTH testing determines the level of hormones in your blood. Your doctor may use this test to help diagnose a condition or determine if further testing is needed. For instance, because ACTH and cortisol production affect blood sugar, you may need testing for diabetes and related conditions.
Who Should Take an Adrenocorticotropic Hormone Blood Test?
You may want to take an ACTH test if you’ve experienced some of the following unexplained symptoms:
- Fatigue
- Skin darkening or discoloration
- Stomach pain or nausea
- Weight gain or loss
- Dizziness
- Weak muscles
ACTH Plasma Test Preparation
You should have your blood drawn between 7 and 10 a.m. for the most reliable results. If you haven’t had a blood test done in a while, here are some tips for a successful lab visit.
ACTH Blood Test Results
The normal ACTH range generally falls between 9 and 52 pg/mL. You should follow up on an irregular result because it could be a sign of a significant medical condition.
Where Can I Get an ACTH Lab Test Near Me?
Scheduling a blood test doesn’t have to be a complicated, frustrating process. Personalabs has more than 400 health tests available at our online store, so you can take care of your health with a simple click. In addition to our comprehensive test selection, we also offer the highest quality of testing through our partnership with Labcorp.
Here’s how it works:
Step 1: Find the test you want, purchase it, then download the accompanying lab order, which you’ll need to bring to the lab. (You may not have to ask your doctor for approval before buying the test; this will depend on the state where you live.)
Step 2: Find the lab closest to you among more than 2,000 locations across the country.
Step 3: Bring the test order to the lab and complete your blood work.
Step 4: View your results, which will be sent to your private Personalabs account within 2 to 10 business days. If you have a specific deadline for receiving your results, contact us and we will work with the lab to fulfill your request.
ACTH testing couldn’t be easier. We give you control over your health.
Frequently Asked Questions
What does the ACTH blood test measure? The ACTH (adrenocorticotropic hormone) test measures the level of ACTH in your blood. ACTH is produced by the pituitary gland and tells the adrenal glands how much cortisol to produce. Testing ACTH helps evaluate the full hypothalamic-pituitary-adrenal (HPA) axis, which governs your stress response, energy, blood pressure, and immune function.
What time of day should I take the ACTH test? ACTH must be collected in the early morning — ideally between 6–8 AM. ACTH follows a strong circadian rhythm, peaking in the morning and declining through the day. Afternoon collection will produce artificially low results. ACTH also degrades rapidly after collection, which is why Labcorp’s certified phlebotomist collection is important for sample integrity.
What conditions does the ACTH test help diagnose? The ACTH test is used to investigate Cushing’s syndrome (excess cortisol causing weight gain, high blood pressure, and fatigue), Addison’s disease (adrenal insufficiency causing chronic fatigue and low blood pressure), adrenal tumors, and unexplained chronic fatigue or weakness with a suspected adrenal component.
What is the difference between an ACTH test and a cortisol test? Cortisol measures the hormone produced by the adrenal glands. ACTH measures the signal from the pituitary that tells the adrenals to produce cortisol. Testing both together helps identify whether an abnormal cortisol result originates in the adrenal glands themselves (primary) or from a pituitary signaling problem (secondary).
Do I need a doctor’s referral to order the ACTH test? No. Personalabs includes a physician-approved lab order with every purchase. No referral or insurance required. HSA and FSA eligible.
