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Mifeprex Side Effects

Generic Name: mifepristone

Note: This page contains information about the side effects of mifepristone. Some of the dosage forms included on this document may not apply to the brand name Mifeprex.

For the Consumer

Applies to mifepristone: oral tablet

In addition to its needed effects, some unwanted effects may be caused by mifepristone (the active ingredient contained in Mifeprex). In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking mifepristone:

Less common:
  • Excessively heavy vaginal bleeding
  • unusual tiredness or weakness
Incidence not known:
  • Chest pain or discomfort
  • confusion
  • cough or hoarseness
  • fast, weak pulse
  • fever or chills
  • lower back or side pain
  • pain or discomfort in the arms, jaw, back, or neck
  • painful or difficult urination
  • pale, cold, or clammy skin
  • shortness of breath
  • sudden increase in stomach or shoulder pain
  • sweating
  • unusual or large amount of vaginal bleeding

Severity: Minor

Some of the side effects that can occur with mifepristone may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Abdominal or stomach pain or uterine cramping
  • back pain
  • diarrhea
  • dizziness
  • headache
  • nausea or vomiting
Less common:
  • Acid or sour stomach
  • anxiety
  • belching
  • cough
  • fainting or lightheadedness when getting up from a lying or sitting position
  • fever
  • flu-like symptoms
  • headache
  • heartburn
  • increased clear or white vaginal discharge
  • indigestion
  • itching of the vagina or genital area
  • lack or loss of strength
  • pain during sexual intercourse
  • pain or tenderness around the eyes and cheekbones
  • pale skin
  • shaking chills
  • shortness of breath or troubled breathing
  • sleeplessness or trouble sleeping
  • stomach discomfort, upset, or pain
  • stuffy or runny nose
  • tightness of the chest or wheezing
  • troubled breathing, exertional
  • unusual bleeding or bruising

For Healthcare Professionals

Applies to mifepristone: oral tablet


Hematologic side effects have included anemia and a decrease in hemoglobin of greater than 2 g/dL in 2% of patients.[Ref]


Genitourinary side effects have included uterine cramping (83%), uterine hemorrhage (9%), vaginitis (3%), leukorrhea (2%), and pelvic pain (2%). Postmarketing reports have included postabortion infection (including endometritis and parametritis) and ruptured ectopic pregnancy. Additional postmarketing reports have included pelvic infection and hematometra. Additional side effects in patients with Cushing syndrome included endometrial hypertrophy.[Ref]


Gastrointestinal side effects have included abdominal pain (96%), nausea (43% to 61%), vomiting (2% to 31%), diarrhea (18% to 26%), and dyspepsia (3%). Additional side effects in patients with Cushing syndrome included decreased appetite, dry mouth, and constipation.[Ref]

Nervous system

Nervous system side effects have included headache (2% to 31%), dizziness (1% to 12%), fatigue (10%), insomnia (3%), asthenia (3%), and fainting (2%). Postmarketing reports have included reports of light headedness and loss of consciousness. Additional side effects in patients with Cushing syndrome included somnolence.[Ref]


Musculoskeletal side effects have included back pain (9%) and leg pain (2%). Additional side effects in patients with Cushing syndrome included arthralgia, myalgia, and pain in extremity.[Ref]


Immunologic side effects have included fever (4%) and viral infections (4%).[Ref]


Psychiatric side effects have included increased anxiety (2%).[Ref]


Cardiovascular side effects have included syncope (1%). Postmarketing reports have included tachycardia (including racing pulse, heart palpitations, and pounding heart. Hypotension, including orthostatic hypotension, has also reported in after marketing use. Additional side effects in patients with Cushing syndrome included hypertension and peripheral edema.[Ref]


Respiratory side effects have included sinusitis (2%). Additional side effects in patients with Cushing syndrome included nasopharyngitis and dyspnea.[Ref]


Hypersensitivity side effects have included shortness of breath, rash, hives and itching.[Ref]


General side effects in patients with Cushing syndrome included pain and fatigue.[Ref]


1. "Product Information. Mifeprex (mifepristone)" Danco Laboratories, New York, NY.

2. "Product Information. Korlym (mifepristone)." Corcept Therapeutics Incorporated, Menlo Park, CA.

Not all side effects for Mifeprex may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.