Will I Experience Side Effects?

As you start treatment with Korlym®, you may experience the effects of cortisol withdrawal, which can feel like you have the flu. Symptoms of cortisol withdrawal include tiredness, headaches, nausea, swelling of your arms and legs, and joint pain.

As the correct amount of Korlym for your body is established, you may see improvements in these symptoms. In the clinical study of Korlym, side effects did not increase with increased dosing.

You should tell your healthcare provider about any symptoms you experience, so that he or she can help.

Please read the information about side effects listed below:

Adrenal insufficiency: This is a condition in which patients experience low blood pressure and low blood sugar along with the symptoms of cortisol withdrawal listed above. Tell your healthcare provider right away if you have any symptoms that could indicate adrenal insufficiency.

Muscle aches, cramps, or palpitations: These could be related to low potassium levels. Although potassium can be found in many foods, low potassium experienced while you are taking Korlym should be treated by your healthcare provider.

Unusual vaginal bleeding: Women sometimes have irregular periods or spotting when taking Korlym. If you notice any signs of irregular vaginal bleeding, tell your primary healthcare provider right away. In addition, make sure to let your gynecologist know you are taking Korlym.

Changes in blood sugar or blood pressure: If you notice higher or lower levels than usual during your regular monitoring, be sure to let your healthcare provider know.

The most common side effects of Korlym include:

  • Nausea
  • Fatigue
  • Vomiting
  • Decreased appetite
  • Pain in your arms and legs (arthralgia)
  • Swelling of your arms and legs
    (peripheral edema)
  • Headache
  • Dizziness
  • High blood pressure
  • Low potassium in your blood
  • Thickening of the lining of the uterus (endometrial hypertrophy)

These are not all of the possible side effects of Korlym. Tell your healthcare provider if you have any side effect that bothers you or that does not go away.


  1. Yuen KCJ, Williams G, Kushner H, Nguyen D. Association between mifepristone dose, efficacy, and tolerability in patients with Cushing syndrome. Endocr Pract. 2015;21(10):1087-1092.
  2. Korlym [package insert]. Menlo Park, CA: Corcept Therapeutics Incorporated; November 2019.

To report a medical adverse event, side effect or a product complaint please call 1-855-844-3270


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.