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Korlym Side Effects

Generic name: mifepristone

Medically reviewed by Last updated on Feb 25, 2024.

Note: This document contains side effect information about mifepristone. Some dosage forms listed on this page may not apply to the brand name Korlym.

Applies to mifepristone: oral tablet.


Oral route (Tablet)

Korlym(TM): Mifepristone has potent antiprogestational effects and will result in the termination of pregnancy. Pregnancy must therefore be excluded before the initiation of treatment or if treatment is interrupted for more than 14 days in females of reproductive potential. Pregnancy should be prevented during treatment and for one month after stopping treatment by the use of a nonhormonal medically acceptable method of contraception unless the patient has had a surgical sterilization.

Oral route (Tablet)

Mifeprex®: Serious and sometimes fatal infections and bleeding occur very rarely following spontaneous, surgical, and medical abortions, including following mifepristone use. Atypical Presentation of Infection: Patients with serious bacterial infections and sepsis can present without fever, bacteremia or significant findings on pelvic examination; use a high index of suspicion to rule out serious infection and sepsis. Bleeding: Prolonged heavy bleeding may be a sign of incomplete abortion or other complications and prompt medical or surgical intervention may be needed. Mifepristone is only available through a restricted program called the mifepristone REMS Program. Before prescribing mifepristone, advise the patient about these serious risks, ensure that she knows what to do if she experiences symptoms of these events, and discuss the medication guide and the patient agreement with her.

Serious side effects of Korlym

Along with its needed effects, mifepristone (the active ingredient contained in Korlym) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking mifepristone:

Less common

Incidence not known

Other side effects of Korlym

Some side effects of mifepristone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

For Healthcare Professionals

Applies to mifepristone: oral tablet.


The most commonly reported adverse reactions were nausea, weakness, fever/chills, vomiting, headache, diarrhea, and dizziness.[Ref]


Very common (10% or more): Hypertension (24%)

Uncommon (0.1% to 1%): Hypotension (0.25%), hot flush

Rare (less than 0.1%): Myocardial infarction, induced Adam-Stokes syndrome, superficial thrombophlebitis

Postmarketing reports: Syncope, fainting, loss of consciousness, hypotension (including orthostatic), light-headedness, tachycardia (including racing pulse, heart palpitations, heart pounding)[Ref]


It was reported that of the 42 Cushing syndrome patients with detectable TSH at baseline, eight (19%) had increases in TSH above the normal range, while remaining asymptomatic. The TSH levels returned to normal in most patients when this drug was discontinued at the end of the study.

Adrenal insufficiency was reported in two subjects (4%) in Study 400. The most typical symptoms of adrenal insufficiency were nausea and decreased appetite. Adrenal insufficiency resolved in both cases with interruption of this drug and/or dexamethasone administration.[Ref]

Very common (10% or more): Thyroid function test abnormal (18%) in patients with Cushing syndrome[Ref]


Very common (10% or more): Nausea (48%), vomiting (26%), dry mouth (18%), diarrhea (12%), constipation (10%), gastric discomfort, abdominal pain

Common (1% to 10%): Light or moderate cramping

Rare (less than 0.1%): Gastric bleeding, necrotising pancreatitis

Postmarketing reports: Dyspepsia, gastroesophageal reflux[Ref]


Very common (10% or more): Uterine contractions or cramping (up to 45%) following prostaglandin intake, endometrial hypertrophy (38%), vaginal bleeding, uterine spasm

Common (1% to 10%): Endometritis, pelvic inflammatory disease, heavy uterine bleeding, prolonged post abortion bleeding, spotting, severe hemorrhage, breast tenderness

Uncommon (0.1% to 1%): Uterine rupture after prostaglandin intake (during induction of second trimester termination of pregnancy or labor induction for fetal death in utero during the third trimester), hemorrhagic shock, salpingitis

Rare (less than 0.1%): Hydatiform mole, ectopic pregnancy, amniotic band syndrome, gestational trophoblastic tumor, uteroplacental apoplexy, bilateral adnexal mass, intrauterine adhesion, ovarian cyst rupture, breast abscess, hematosalpinx, uterine rupture

Postmarketing reports: Post-abortal infection (including endometritis, endomyometritis, parametritis, pelvic infection, pelvic inflammatory disease, salpingitis); hematometra, leukorrhea, vaginal hemorrhage, metrorrhagia[Ref]

Heavy bleeding occurs in about 5% of the cases and may require hemostatic curettage in up to 1.4% of the cases.

In clinical trials surgical evacuation was needed in 10% to 12% of women, with some studies reporting a rate as high as 20% to 30%. Bleeding can be prolonged for several days after prostaglandin analog administration and sometimes leads to a decrease in hemoglobin levels.[Ref]


Very common (10% or more): Blood potassium decreased (34%) in Cushing syndrome patients

Rare (less than 0.1%): Thrombotic thrombocytopenic purpura, thrombocytopenia, induced systemic lupus erythematosus

Postmarketing reports: Anemia[Ref]


In Cushing syndrome patients:

Very common (10% or more): Decreased appetite (20%), anorexia (10%)

Postmarketing reports: Increased triglycerides, hypoglycemia[Ref]


Very common (10% or more): Arthralgia (30%), back pain (16%), myalgia (14%), pain in the extremity (12%)

Rare (less than 0.1%): Limb spasm

Postmarketing reports: Muscular weakness, flank pain, musculoskeletal chest pain[Ref]

Nervous system

Very common (10% or more): Headache (44%), dizziness (22%), somnolence (10%)

Rare (less than 0.1%): Vagal symptoms (hot flushes, dizziness, chills), epilepsy, neurogenic tinnitus[Ref]


Very common (10% or more): Fatigue (48%), peripheral edema (26%), pain (14%), chill, fever

Common (1% to 10%): Fainting

Rare (0.01% to 0.1%): Malaise

Very rare (less than 0.01%): Fatal toxic shock caused by Clostridium sordellii endometritis or Escherichia coli (use of mifepristone (the active ingredient contained in Korlym) followed by non authorized vaginal administration of misoprostol oral tablets)

Postmarketing reports: Asthenia, edema, pitting edema, thirst[Ref]


Very common (10% or more): Anxiety (10%)

Rare (less than 0.1%): Mania

Postmarketing reports: Insomnia[Ref]


Very common (10% or more): Dyspnea (16%), sinusitis (14%), nasopharyngitis (12%)

Rare (less than 0.1%): Bronchospasm, induced bronchial asthma

Frequency not reported: Shortness of breath[Ref]


Uncommon (0.1% to 1%): Skin rashes (0.2%), pruritus

Rare (0.01% to 0.1%): Urticaria, erythroderma, erythema nodosum, toxic epidermal necrolysis

Very rare (less than 0.01%): Angioedema[Ref]


Rare (less than 0.1%): Abnormal liver function tests, hepatic failure, hepatorenal failure[Ref]


Rare (less than 0.1%): Anaphylaxis

Postmarketing reports: Allergic reaction (including anaphylaxis, angioedema, hives, rash, itching)[Ref]


Rare (less than 0.1%): Ophthalmoplegia, periorbital edema[Ref]


Rare (less than 0.1%): Elevated alpha-feto protein, elevated carcinoembryonic antigen[Ref]


Rare (less than 0.1%): Renal failure[Ref]


1. (2001) "Product Information. Mifeprex (mifepristone)." Danco Laboratories

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

4. (2012) "Product Information. Korlym (mifepristone)." Corcept Therapeutics Incorporated

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.