How Is Cushing Syndrome Diagnosed?

Your healthcare provider may run several tests to see if you have Cushing syndrome (also called hypercortisolism):

Dexamethasone suppression test (DST)
This test is designed to see if your body is regulating cortisol normally. If it is, taking dexamethasone, which is like cortisol, should send a signal to reduce the amount of cortisol being made by your body.

Late-night salivary cortisol (LNSC)
Measures the amount of cortisol in the saliva at the point when it should be at its lowest level.

Urine free cortisol (UFC)
Measures the amount of cortisol in the urine over 24 hours to detect overproduction.

Please note:

  • The DST or the LNSC, rather than the UFC, is recommended for patients who are suspected of having less severe Cushing syndrome
  • LNSC seems to be the best early predictor of recurrence of Cushing Disease (pituitary source)


  1. Raff H, Carroll T. Cushing’s syndrome: from physiological principles to diagnosis and clinical care. J Physiol. 2015;593(3):493-506.
  2. Fleseriu M, Hamrahian AH, Hoffman AR, Kelly DF, Katznelson L; for AACE Neuroendocrine and Pituitary Scientific Committee. American Association of Clinical Endocrinologists and American College of Endocrinology disease state clinical review: diagnosis of recurrence in Cushing’s disease. Endocr Pract. 2016;22(12):1436-1448.


Most Important Information About Korlym

Korlym should never be taken by women who are pregnant or who might become pregnant. Taking Korlym during pregnancy will result in the loss of a pregnancy. A pregnancy test is required before starting Korlym or if treatment is interrupted for more than 14 days. Talk with your doctor about how to prevent pregnancy.

Tell your doctor and pharmacist about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Korlym and certain other medicines, may affect each other or may cause side effects.

Do not take Korlym if:

  • you are taking certain medications for high cholesterol, such as simvastatin (e.g., Zocor®) or lovastatin (e.g., Mevacor®), as Korlym may cause a dangerous increase in the level of these medications in the blood
  • you take corticosteroid medications like prednisone to treat a serious medical condition
  • you have experienced unexplained vaginal bleeding, changes in the cells lining your uterus (endometrial hyperplasia), or cancer of the lining of your uterus (endometrial cancer)

What Are the Possible Side Effects of Korlym?

Patients taking Korlym should be monitored for side effects. Potential serious side effects include signs of adrenal insufficiency, low potassium levels, changes to the lining of the uterus, vaginal bleeding, and problems with the electrical system of the heart.

The most common side effects of Korlym include nausea, fatigue, headache, low potassium in the blood, pain in arms and legs (arthralgia), vomiting, swelling of arms and legs (peripheral edema), high blood pressure, dizziness, decreased appetite, and thickening of the lining of the uterus (endometrial hypertrophy).

Tell your doctor if you have any side effect that bothers you or that does not go away.

These are not all of the possible side effects of Korlym. For more information, ask your doctor or pharmacist. For medical advice about side effects, call your doctor.

Before taking Korlym, talk to your doctor if you are breastfeeding or plan to breastfeed.

Complete warnings and other important safety information are available in the full Prescribing Information and Medication Guide.

What Is Korlym® (mifepristone) 300 mg Tablets?

Korlym is a prescription medicine used to treat high blood sugar (hyperglycemia) caused by high cortisol levels in the blood (hypercortisolism) in adults with endogenous Cushing syndrome who have type 2 diabetes mellitus or glucose intolerance and who cannot have surgery or for whom surgery has failed. Korlym is not for people who have type 2 diabetes mellitus not caused by Cushing syndrome.