Mifepristone

Mifepristone is a selective antagonist of the progesterone receptor at low doses and blocks the glucocorticoid receptor (GR-II) at higher doses. Mifepristone has high affinity for the GR-II receptor but little affinity for the GR-I (MR, mineralocorticoid) receptor.

• KORLYM (mifepristone) is a cortisol receptor blocker indicated to control hyperglycemia secondary to hypercortisolism in adult patients with endogenous Cushing's syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery. LIMITATIONS OF USE: KORLYM should not be used in the treatment of patients with type 2 diabetes unless it is secondary to Cushing's syndrome.ICD-10: E11.9

• KORLYM is contraindicated in: Pregnancy [See Dosage and Administration ( 2.1 ), Use in Specific Populations ( 8.1 , 8.3 )] Patients taking drugs metabolized by CYP3A such as simvastatin, lovastatin, and CYP3A substrates with narrow therapeutic ranges, such as cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, due to an increased risk of adverse events. [See Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Patients receiving systemic corticosteroids for lifesaving purposes (e.g., immunosuppression after organ transplantation) because KORLYM antagonizes the effect of glucocorticoids.contraindicated

Obtain a negative pregnancy test in females of reproductive potential prior to initiating treatment with KORLYM or if treatment is interrupted for more than 14 days. ( 2.1 ) Administer once daily orally with a meal ( 2.2 ). The recommended starting dose is 300 mg once daily ( 2.2 ). Based on clinical response and tolerability, the dose may be increased in 300 mg increments to a maximum of 1200 mg once daily. Do not exceed 20 mg/kg per day ( 2.2 ). Renal impairment: do not exceed 600 mg once daily ( 2.3 ). Mild-to-moderate hepatic impairment: do not exceed 600 mg once daily. Do not use in severe hepatic impairment ( 2.4 ). Concomitant administration with strong CYP3A inhibitors: Do not exceed 900 mg once daily ( 2.5 ). 2.1 Testing Prior to and During KORLYM Administration Obtain a negative pregnancy test in females of reproductive potential prior to initiating treatment with KORLYM or if treatment is interrupted for more than 14 days [see Contraindications ( 4 ), Warnings and Precautions ( 5.2 ), Use in Specific Populations ( 8.1 , 8.3 )]. 2.2 Adult Dosage The recommended starting dose is 300 mg orally once daily. KORLYM must be given as a single daily dose. KORLYM should always be taken with a meal. Patients should swallow the tablet whole. Do not split, crush, or chew tablets. Dosing and titration The daily dose of KORLYM may be increased in 300 mg increments. The dose of KORLYM may be increased to a maximum of 1200 mg once daily but should not exceed 20 mg/kg per day. Increases in dose should not occur more frequently than once every 2-4 weeks.

Adrenal insufficiency : Patients should be closely monitored for signs and symptoms of adrenal insufficiency ( 5.1 ). Hypokalemia : Hypokalemia should be corrected prior to treatment and monitored for during treatment ( 5.2 ). Vaginal bleeding and endometrial changes : Women may experience endometrial thickening or unexpected vaginal bleeding. Use with caution if patient also has a hemorrhagic disorder or is on anti-coagulant therapy ( 5.3 ). QT interval prolongation : Avoid use with QT interval-prolonging drugs, or in patients with potassium channel variants resulting in a long QT interval ( 5.4 ). Use of Strong CYP3A Inhibitors: Concomitant use can increase mifepristone plasma levels. Use only when necessary and limit mifepristone dose to 900 mg ( 5.6 ). 5.1 Adrenal Insufficiency Patients receiving mifepristone may experience adrenal insufficiency. Because serum cortisol levels remain elevated and may even increase during treatment with KORLYM, serum cortisol levels do not provide an accurate assessment of hypoadrenalism in patients receiving KORLYM. Patients should be closely monitored for signs and symptoms of adrenal insufficiency, including weakness, nausea, increased fatigue, hypotension, and hypoglycemia. If adrenal insufficiency is suspected, discontinue treatment with KORLYM immediately and administer glucocorticoids without delay. High doses of supplemental glucocorticoids may be needed to overcome the glucocorticoid receptor blockade produced by mifepristone.

Most common adverse reactions in Cushing's syndrome (≥ 20%): nausea, fatigue, headache, decreased blood potassium, arthralgia, vomiting, peripheral edema, hypertension, dizziness, decreased appetite, endometrial hypertrophy ( 6 ). To report suspected adverse reactions, contact Corcept Therapeutics at 1-855-844-3270 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed cannot be directly compared to rates in other clinical trials and may not reflect the rates observed in clinical practice. Safety data on the use of KORLYM are available from 50 patients with Cushing's syndrome enrolled in an uncontrolled, open-label, multi-center trial (Study 400). Forty-three patients had Cushing's disease and all except one had previously undergone pituitary surgery. Four patients had ectopic ACTH secretion, and three had adrenal carcinoma. Patients were treated for up to 24 weeks. A dose of 300 mg per day was administered for the initial 14 days; thereafter, the dose could be escalated in increments of 300 mg per day based on assessments of tolerability and clinical response. Doses were escalated up to 900 mg per day for patients <60 kg, or 1200 mg per day for patients >60 kg.

8.1 Pregnancy Risk Summary KORLYM is contraindicated in pregnancy because the use of KORLYM results in pregnancy loss. There are no data that assess the risk of birth defects in women exposed to KORLYM during pregnancy. Available data limited to exposure following a single dose of mifepristone during pregnancy showed a higher rate of major birth defects compared to the general population comparator (See Data ) . Mifepristone administered to pregnant mice, rats, and rabbits during organogenesis caused pregnancy loss in all species at clinically relevant doses based on body surface area comparisons (See Data ) . The inhibition of both endogenous and exogenous progesterone by mifepristone at the progesterone receptor results in pregnancy loss. If KORLYM is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. [See Contraindications ( 4 )] The estimated risk of fetal loss is elevated in patients with active Cushing's syndrome (24-30%), and the risk of major birth defects is unknown. In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2-4% and 15-20%, respectively. Data Human Data There are no data on long term exposure to mifepristone in pregnancy.

Metabolism

Absorption Following oral administration, time to peak plasma concentrations of mifepristone occurred between 1 and 2 hours following single dose, and between 1 and 4 hours following multiple doses of 600 mg of KORLYM in healthy volunteers. Mean plasma concentrations of three active metabolites of mifepristone peak between 2 and 8 hours after multiple doses of 600 mg/day, and the combined concentrations of the metabolites exceed that of the parent mifepristone.

There is no experience with overdosage of KORLYM.

• Feb 17, 2012NDANDA202107Corcept Therap
• Apr 11, 2019ANDAANDA091178Genbiopro
• Aug 3, 2020ANDAANDA211436Teva Pharms Usa Inc
• Sep 30, 2025ANDAANDA216616Evita Solutions

1. 1Nausea79017%
2. 2Fatigue69015%
3. 3Blood Potassium Decreased4489.7%
4. 4Vomiting4289.3%
5. 5Dizziness3978.6%
6. 6Headache3828.3%
7. 7Haemorrhage3617.8%
8. 8Blood Pressure Increased3417.4%
9. 9Abortion Incomplete3357.2%
10. 10Blood Glucose Increased3086.7%
11. 11Asthenia2826.1%
12. 12Pain2776.0%
13. 13Decreased Appetite2735.9%
14. 14Blood Glucose Decreased2675.8%
15. 15Peripheral Swelling2465.3%

Recent PubMed references pinned to Mifepristone as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Very early medical abortion before confirmed intrauterine pregnancy.
  Danish medical journal · 2026 · Kallfa E, Karstensen SH, Møller BF, et al.
  PMID 42095309DOI 10.61409/A11250983
• Formulation-Based Repurposing of Mifepristone Using a Drug-Eluting Intrauterine Insert for Localized Uterine Fibroid Therapy: A Preclinical Study.
  AAPS PharmSciTech · 2026 · Patel R, Patel A, Patel G, et al.
  PMID 42014532DOI 10.1208/s12249-026-03404-8
• Chronic mifepristone administration induces obese sarcopenia, hepatic steatosis and insulin resistance in androgen-deprived male mice.
  The Journal of steroid biochemistry and molecular biology · 2026 · Shang J, Yan K, Liu L, et al.
  PMID 41985637DOI 10.1016/j.jsbmb.2026.107025
• Outcome of Mid Trimester Termination of Pregnancy in Previous Caesarian Section By Combined Mifepristone and Misoprostol.
  Mymensingh medical journal : MMJ · 2026 · Sultana N, Latif T, Nahar M, et al.
  PMID 41914082
• Computational modeling-directed combination treatment with etanercept and mifepristone mitigates neuroinflammation in a mouse model of Gulf War Illness.
  PloS one · 2026 · Kelly KA, Felton CM, Billig BK, et al.
  PMID 41843558DOI 10.1371/journal.pone.0324577
• Low-dose mifepristone for the management of refractory heavy menstrual bleeding in women with bleeding disorders: a retrospective study.
  BMC women's health · 2026 · Jiang X, Zhu Y, Su D, et al.
  PMID 41832474DOI 10.1186/s12905-026-04354-w
• Comparative analysis of social issues toward medical abortion using mifepristone in South Korea and the United States: Topic modeling and sentiment analysis.
  PloS one · 2026 · Ko M, Park DY, Oh JM, et al.
  PMID 41790588DOI 10.1371/journal.pone.0342848
• Glucocorticoid receptor blockade reverses heroin and alcohol withdrawal-induced hyperalgesia in rats.
  Neuropharmacology · 2026 · Skandan N, Acosta VP, Vendruscolo JCM, et al.
  PMID 41763299DOI 10.1016/j.neuropharm.2026.110896

The 10 most recently updated of 218 ClinicalTrials.gov registrations naming Mifepristone as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Surgical vs. Medical Abortion on Sexual Function After Early Pregnancy Loss
  Completed · Interventional · 88 enrolled · Harran University
  NCT07646275updated 2026-06-12
• Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive
  Active not recruiting · Phase 3 · Interventional · 615 enrolled · Leiden University Medical Center
  NCT06394999updated 2026-06-08
• Patient Agreement Form and Medication Abortion Knowledge
  Completed · Interventional · 637 enrolled · University of California, San Francisco
  NCT07604675updated 2026-05-22
• Simultaneous Mifepristone and Misoprostol Versus Misoprostol Alone for Induction of Labor of Nonviable Second Trimester Pregnancy: a Pilot Randomized Controlled Trial
  Completed · Phase 4 · Interventional · 30 enrolled · Washington University School of Medicine
  NCT05322252updated 2026-04-07
• Comparison Between Letrozole and Mifepristone in Medical Termination of First Trimester Miscarriages
  Completed · Phase 3 · Interventional · 120 enrolled · Calcutta National Medical College and Hospital
  NCT05304273updated 2026-04-02
• Optimal Time Interval Between Mifepristone and Misoprostol Administration for Early Pregnancy Loss
  Not yet recruiting · Phase 3 · Interventional · 1,000 enrolled · University of Pennsylvania
  NCT07506512updated 2026-04-01
• A Study of Enzalutamide, Enzalutamide in Combination With Mifepristone, or Chemotherapy in People With Metastatic Breast Cancer
  Recruiting · Phase 2 · Interventional · 201 enrolled · Memorial Sloan Kettering Cancer Center
  NCT06099769updated 2026-02-25
• A Real-World Study Comparing the Efficacy of Different Treatment Regimens for Early Missed Abortion
  Recruiting · Interventional · 580 enrolled · The Third Xiangya Hospital of Central South University
  NCT07422506updated 2026-02-20
• Study of Pembrolizumab and Mifepristone in Patients With Advanced HER2-negative Breast Cancer
  Terminated · Phase 2 · Interventional · 24 enrolled · University of Chicago
  NCT03225547updated 2025-12-23
• The Misoprostol-Only Regimen Evidence Study
  Not yet recruiting · Phase 4 · Interventional · 1,900 enrolled · Ibis Reproductive Health
  NCT07174856updated 2025-10-08

Frequently asked questions

How does Mifepristone work?

Mifepristone is a selective antagonist of the progesterone receptor at low doses and blocks the glucocorticoid receptor (GR-II) at higher doses. Mifepristone has high affinity for the GR-II receptor but little affinity for the GR-I (MR, mineralocorticoid) receptor.

What is Mifepristone used for?

According to FDA labeling, Mifepristone carries indications including: KORLYM (mifepristone) is a cortisol receptor blocker indicated to control hyperglycemia secondary to hypercortisolism in adult patients with endogenous Cushing's syndrome who have type 2 diabetes mellitus or glucose intolerance and have failed surgery or are not candidates for surgery. LIMITATIONS OF USE: KORLYM should not be used in the treatment of patients with type 2 diabetes unless it is secondary to Cushing's syndrome.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Mifepristone?

Mifepristone is classified as Progesterone receptor modulators, Progestin Antagonist, Glucocorticoid Receptor Antagonists, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Progestational Hormone Receptor Antagonists, Decreased Ovarian Progesterone Secretion.

What are the brand names for Mifepristone?

Mifepristone is marketed under brand names including Korlym, Mifeprex.

What are the contraindications for Mifepristone?

Mifepristone labeling lists contraindications including: KORLYM is contraindicated in: Pregnancy [See Dosage and Administration ( 2.1 ), Use in Specific Populations ( 8.1 , 8.3 )] Patients taking drugs metabolized by CYP3A such as simvastatin, lovastatin, and CYP3A substrates with narrow therapeutic ranges, such as cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, due to an increased risk of adverse events. [See Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Patients receiving systemic corticosteroids for lifesaving purposes (e.g., immunosuppression after organ transplantation) because KORLYM antagonizes the effect of glucocorticoids.. Always consult the full prescribing information and a clinician.