Mifepristone: Common Uses, How to Take, & Side Effects

Updated in December 2023

Mifepristone is a synthetic steroid that is used for legal medical abortion up to 70 days of gestation. It can also be used to manage high blood sugar levels secondary to endogenous Cushing’s syndrome. 

This medication causes fetal death when used during pregnancy, and should not be taken without a doctor’s prescription. It can also cause side effects like vaginal bleeding, abdominal pain and nausea. 

Mifepristone is available in pill form, in doses of 200 and 300 mg. You should only take it as directed by your doctor. 

Imagem ilustrativa número 1

Common uses

Mifepristone is approved for use by the FDA for legal medical abortion up to 70 days of gestation. It is commonly used in combination with misoprostol. It can also be indicated for the treatment of hyperglycemia caused by Cushing’s syndrome. 

Difference between mifepristone and misoprostol 

Mifepristone is a synthetic steroid that blocks progesterone and other corticosteroid activity. It stimulates cortisol production in the body and destabilizes the uterine well, which leads to miscarriage. 

Misoprostol is a synthetic prostaglandin that acts specifically on the muscle of the uterine wall to stimulate contractions. Learn more about misoprostol and how it is taken. 

How to take

Mifepristone use depends on the use it is prescribed for. The recommended doses are as follows: 

  • Inducing miscarriage: One mifepristone 200 mg pill taken orally as a single dose, followed by misoprostol 800 mcg absorbed bucally (taken as eight misoprostol 100 mcg pills or four 200 mcg pills). The misoprostol is applied on the gums or inside of the cheeks and dissolved for 30 minutes. You can then swallow any remnants with water. 
  • Hyperglycemia secondary to endogenous Cushing’s: One mifepristone 300 mg pill with a meal, daily. This dose can be increased by an additional pill every 2 to 4 weeks, to a maximum of 1200 mg per day. 

Mifepristone should only be taken as prescribed, especially if taken during pregnancy, as it can put the mother and baby’s health at risk. 

Side effects

The most common side effects of mifepristone include:

  • Abdominal pain
  • Vaginal bleeding
  • Nausea
  • Vomiting
  • Weakness
  • Fever 
  • Headache
  • Dizziness
  • Loss of appetite
  • Diarrhea 
  • General malaise

The vaginal bleeding tends to be heavier than that of a normal period, however the other side effects are typically mild in intensity. 

In addition, mifepristone can also cause changes to blood pressure, potassium levels, and blood sugar. In more serious cases, it can lead to fetal death and allergic reactions, like anaphylaxis.  

Contraindications for use

Mifepristone is not indicated for patients with allergies to this medication or prostaglandin. Patients with vaginal bleeding of an undetermined cause, endometrial cancer, adrenal insufficiency, ectopic pregnancy or coagulation diseases should not take this medication.

It should also be avoided by those taking anticoagulants, frequent corticosteroids, simvastatin, lovastatin, or antifungals. Mifepristone is not advised for women wanting to continue their pregnancy.