ACTH (Cosyntropin) Stimulation Test

The following information is provided to help you understand why it may be necessary to have an ACTH stimulation test done. If you have any questions or concerns please contact your doctor or the nearest emergency room immediately.

What are the benefits of having an ACTH Stimulation Test?

In addition to being able to diagnose possible causes of low testosterone levels, the ACTH test can also provide some helpful information on how much testosterone you actually produce. You can learn more about this here:

How does an ACTH Stimulation Test work?

An ACTH stimulation test measures your body’s production of the hormone cortisol. Cortisol is a stress hormone produced in response to physical or emotional stressors. It is also known as the “fight or flight” hormone. When we are in danger, our brain secretes ACTH (adrenocorticotropic hormone) which tells the adrenal glands to produce cortisol.

The test is done by taking a blood sample before and after injecting you with the hormone. Your levels are then compared to determine your ability to produce cortisol.

Before taking part in an ACTH stimulation test, tell your doctor about any medications that you are taking. Certain medicines can influence the results of the test.

Since this is an invasive tests that requires a blood draw, it is not used frequently to test for abnormal cortisol levels. It is mainly used to verify diagnoses of Cushing’s Syndrome and hypothalamic dysfunction.

What are the risks of having an ACTH Stimulation Test?

As with any injection, there is a risk of bruising at the injection site. As previously stated, you may also experience some anxiety from being in a hospital environment.

How do I prepare for an ACTH Stimulation Test?

You should tell your doctor about any medications that you are taking since certain drugs can interfere with the results.

How is an ACTH (cosyntropin) stimulation test performed?

Your doctor or a lab technician will clean the injection site with alcohol and allow it to dry. Next, they will inject you with a synthetic form of ACTH called cosyntropin. This can be done in either of two locations:

You will get your blood drawn before the injection so that the lab can determine the baseline level of cortisol in your body.

The injection can cause muscle aches, fatigue, or a drop in blood pressure. Tell your physician if you experience any of these.

How long does an ACTH (cosyntropin) stimulation test take?

The entire procedure takes about two hours.

What is the cost of an ACTH (cosyntropin) stimulation test?

Due to the cost of the medication and the medical instruments needed to perform this test, the price can run between $300-500. It is not usually covered by insurance.

What do the results mean?

An ACTH stimulation test measures your adrenal glands’ production of cortisol in response to an injected cosyntropin. The higher the level of cortisol, the more your body is producing it on its own. This means that the pituitary gland is not having the desired effect on the adrenal glands.

How is the ACTH stimulation test treated?

If you have abnormal cortisol levels, your physician will treat the underlying cause of your pituitary gland malfunction. This may involve surgery to remove a tumor or lesion from the brain or may entail the use of medication to reduce swelling of the brain.

You should also talk to your physician about any ongoing medications that you are taking since they may be contributing to the problem.

What are the benefits of an ACTH (cosyntropin) stimulation test?

This is a relatively non-invasive test and gives your physician valuable information about the health of your pituitary gland.

Who should have an ACTH (cosyntropin) stimulation test?

You should have this test if you have been diagnosed with primary adrenal insufficiency which can be due to tumors or other swelling of the pituitary gland.

If your primary care physician suspects that your pituitary tumor may be overproducing ACTH, he or she may send you to a specialist in pituitary disorders for further testing.

Sources & references used in this article:

Use of a low‐dose ACTH stimulation test for diagnosis of hypoadrenocorticism in dogs by P Lathan, GE Moore, S Zambon… – Journal of veterinary …, 2008 – Wiley Online Library

The corticotropin-releasing hormone stimulation test in patients with panic disorder by W Gallucci, GP Chrousos, PW Gold – Am J Psychiatry, 1986 – Citeseer

The corticotropin-releasing factor stimulation test: an aid in the evaluation of patients with Cushing’s syndrome by GP Chrousos, HM Schulte, EH Oldfield… – … England Journal of …, 1984 – Mass Medical Soc