Mifepristone

How Does Mifepristone Work?

Mifepristone works as a hormone receptor blocker with a dose-dependent dual mechanism. At low doses (200 mg for abortion), it competitively binds to progesterone receptors — more tightly than progesterone itself — without activating them. This prevents progesterone from maintaining the uterine lining, causing the embryo to detach, the cervix to soften, and the uterus to become sensitive to prostaglandins. When misoprostol (a prostaglandin analog) is taken 24-48 hours later, it induces uterine contractions to expel the pregnancy.

At high doses (300-1200 mg for Cushing's syndrome as Korlym), mifepristone also blocks glucocorticoid receptors — the receptors cortisol uses to raise blood sugar. By blocking these receptors, mifepristone prevents cortisol from causing hyperglycemia, even though blood cortisol levels may rise further as the body compensates. Mifepristone is rapidly absorbed (peak levels at ~90 min), is 98% protein-bound, and is metabolized primarily by CYP3A4 with a terminal half-life of approximately 18 hours.

How Hard Is It to Find Mifepristone In Stock?

Mifepristone is one of the most access-restricted prescription drugs in the United States. The FDA's REMS Program requires that both prescribers and pharmacies be certified before mifepristone can be prescribed or dispensed. Most retail pharmacies — including the majority of major chain locations — have not completed REMS certification. Research shows that since the 2023 REMS update allowing retail pharmacy dispensing, less than 2% of mifepristone prescriptions filled at retail have been at in-store pharmacies; most are filled through mail-order pharmacies connected to telehealth services.

Access is further complicated by state laws. As of June 2026, 13 states have total abortion bans. Many others have gestational limits, telehealth restrictions, or specific mifepristone dispensing requirements. The legal landscape is evolving rapidly — a May 2026 Fifth Circuit ruling that would have reimposed in-person dispensing was stayed by the Supreme Court, but further changes remain possible.

Finding a certified pharmacy that carries mifepristone in your area can be frustrating. medfinder calls pharmacies near you on your behalf to find out which ones can fill your mifepristone prescription, then texts you the results. This is significantly more efficient than calling pharmacies yourself.

Who Can Prescribe Mifepristone?

For the abortion indication (Mifeprex), prescribers must be certified under the FDA's Mifepristone REMS Program. Certification requires completing and signing a Prescriber Agreement Form attesting to clinical qualifications. Mifepristone is not a federally controlled substance, so no DEA registration is required. However, state law may impose additional requirements in some states.

REMS-eligible prescriber types include:

• Obstetrician-Gynecologists (OB-GYNs)
• Family Medicine Physicians
• Internists and General Practitioners
• Nurse Practitioners (NPs) — authorized to prescribe in their state and meeting REMS clinical requirements
• Physician Assistants (PAs) — authorized to prescribe in their state and meeting REMS requirements
• Certified Nurse Midwives (CNMs)
• Endocrinologists (for Korlym/Cushing's syndrome indication)

Telehealth availability: In states where abortion is legal and telehealth prescribing is not specifically prohibited by state law, mifepristone can be prescribed via telehealth by REMS-certified providers and mailed through certified pharmacies. As of June 2026, the Supreme Court has stayed the Fifth Circuit ruling that would have eliminated telehealth prescribing — so telehealth access is currently preserved in states where it is legally permitted.

Is Mifepristone a Controlled Substance?

Mifepristone is NOT a federally scheduled controlled substance under the DEA. You do not need a DEA-controlled substance prescription, and pharmacies do not need a DEA registration specifically for mifepristone. However, mifepristone is subject to the FDA's Mifepristone REMS Program, which imposes certification requirements on both prescribers and dispensing pharmacies that are more restrictive than those for most non-controlled prescription drugs.

Notable exception: Louisiana has enacted a state law classifying mifepristone as a state-level controlled substance. In Louisiana, providers and pharmacies must comply with controlled substance regulations under state law. This law is being challenged in state court. Patients and providers in Louisiana should consult current state legal guidance. No other state has enacted a similar state-controlled substance designation as of June 2026, though legislative activity in other states may change this.

Common Side Effects of Mifepristone

For medical abortion (Mifeprex + misoprostol):

• Heavy vaginal bleeding with clots (expected; signals the medication is working)
• Abdominal cramping and pain
• Nausea and vomiting
• Diarrhea
• Low-grade fever and chills (first 24 hours)
• Headache and dizziness

For Cushing's syndrome (Korlym) — common side effects (≥20%):

• Nausea, fatigue, headache
• Decreased blood potassium (hypokalemia)
• Joint pain, peripheral edema, high blood pressure

Serious side effects — seek emergency care:

• Soaking more than 2 maxi pads/hour for 2+ hours (hemorrhage risk)
• Serious infection or sepsis (may occur without fever — watch for malaise, rapid heartbeat)
• QT prolongation / heart rhythm changes (Korlym)
• Adrenal insufficiency (Korlym)

Final Thoughts on Mifepristone

Mifepristone is a safe, effective, and FDA-approved medication with a more than 25-year track record. Its clinical utility is well-established — as a medical abortion option, it is used in approximately two-thirds of US abortions, and as Korlym, it fills an important niche for Cushing's syndrome patients who have failed surgical treatment. However, access remains a significant challenge due to the REMS program, state laws, and legal battles over dispensing requirements.

For patients, the most common obstacle is not the prescription — it's finding a certified pharmacy that can fill it. Most retail pharmacies are not REMS-certified, major chains have inconsistent participation, and the legal landscape can change quickly. Knowing your resources ahead of time makes a meaningful difference.

If you're struggling to find a pharmacy that carries mifepristone, medfinder can call pharmacies near you to identify which ones are REMS-certified and can fill your prescription — then texts you the results. It's a paid service designed to take the burden of pharmacy searching off your plate so you can focus on what matters.