The most widely used abortion medication in the United States has spent the better part of three years fighting for its survival in the courts, its future shaped as much by politics and ideology as by science.
Mifepristone, approved by the US Food and Drug Administration (FDA) in September 2000, now accounts for more than 60% of all abortions in the country, according to data compiled by KFF. Over 7.5 million people have used it since its original approval. Yet despite its established safety record, a years-long legal assault has placed it at the centre of America's most charged and consequential reproductive rights battle.
The US Supreme Court intervened decisively in June 2024, unanimously blocking an attempt to strip the drug off the market. However, new litigation, now proceeding in a federal court in Missouri, means the drug's access remains legally vulnerable.
What Mifepristone Is and How It Works
Mifepristone is a synthetic steroid that blocks progesterone, the hormone necessary to sustain a pregnancy. The drug, used together with misoprostol, is approved to end an intrauterine pregnancy through ten weeks' gestation. The two-drug regimen was first developed in France in the 1980s and was known there as RU-486, a designation that became shorthand for the culture war that followed it across the Atlantic.
The FDA approved mifepristone for early pregnancy termination in 2000. Today, mifepristone in combination with misoprostol is the most widely used abortion regimen in the US and is also widely used throughout the world. Between 2016 and 2021, the FDA expanded its conditions of use, extending the gestational limit from seven to ten weeks, permitting mail dispensing, and allowing telemedicine prescriptions.
🚨 JUST IN: The US Supreme Court has temporarily RESTORED broad access to abortion pill mifepristone, overturning a lower court ruling
— Eric Daugherty (@EricLDaugh) May 4, 2026
Louisiana argued that letting the pill be mailed makes its abortion ban "moot"
SCOTUS MUST do the right thing and reverse course!
This would… pic.twitter.com/AMaMM5mif1
The Legal Assault: From a Texas Courtroom to the Supreme Court
The legal battle began in November 2022, weeks after the Supreme Court's Dobbs v. Jackson Women's Health Organization ruling overturned Roe v. Wade. The Alliance for Hippocratic Medicine (AHM), a coalition of anti-abortion medical organisations and physicians, filed suit in a US federal district court in Texas. The case was strategically assigned to Judge Matthew Kacsmaryk, a Trump appointee in Amarillo, Texas, whose court anti-abortion groups had long targeted for favourable rulings.
In April 2023, US District Judge Kacsmaryk issued a preliminary injunction suspending the FDA's approval of mifepristone, thereby ordering the drug off the market. The ruling sent shockwaves through the medical and pharmaceutical sectors. The Department of Justice appealed on 10 April 2023, and on 14 April, the US Supreme Court issued a temporary stay, preventing the district court's order from taking effect.
On 16 August 2023, the Fifth Circuit Court of Appeals ruled to reinstate burdensome pre-2016 restrictions on mifepristone, but did not remove the drug from the market. The government petitioned the Supreme Court, which agreed in December 2023 to hear the consolidated case FDA v. Alliance for Hippocratic Medicine.
The Supreme Court's Unanimous Verdict
Oral arguments were heard on 26 March 2024. Court observers noted at the time that a majority of justices appeared sceptical of the challengers' standing claims. Their instincts proved correct.
On 13 June 2024, the Supreme Court ruled unanimously. Justice Brett Kavanaugh, writing for the Court, held that 'sincere legal, moral, ideological, and policy objections to elective abortion and to the FDA's relaxed regulation of an abortion drug alone do not establish a justiciable case or controversy in federal court'.
The Court's reasoning was procedural rather than substantive. The plaintiffs were anti-abortion physicians and a medical association, none of whom prescribed mifepristone or performed abortions. None of them had been required by FDA action to do so. Their only claimed injury was the hypothetical scenario that a patient might seek emergency care following a complication from taking mifepristone, an injury the Court found too speculative to confer standing.
The Court did not comment at all about the demonstrable and unequivocal evidence of the safety of mifepristone, or anything about the appropriateness of the FDA's regulatory decisions. That silence was deliberate: the ruling left the door open for future challengers to find a plaintiff with cognisable legal injury. The organisation formally withdrew its claims in November 2024.
The Fight Continues: New Lawsuits, New Threats
The Supreme Court's ruling did not end the litigation. On 16 January 2025, Judge Kacsmaryk ruled that the Republican-led states of Idaho, Missouri, and Kansas could proceed with a separate lawsuit seeking to restrict mifepristone's availability. The states claim the FDA's loosened distribution rules allow abortion pills to cross their borders, undermining their own state-level bans.
In October 2025, Kacsmaryk transferred the case to the Eastern District of Missouri in St Louis, writing that he had no jurisdiction over the remaining plaintiffs. The amended complaint, now proceeding in Missouri, seeks to roll back the drug's gestational limit from ten weeks to seven, reinstate in-person dispensing requirements, and remove the FDA's approval of the generic version of mifepristone produced by GenBioPro.
GenBioPro, the sole US manufacturer of generic mifepristone, intervened in the case. In a statement, CEO Evan Masingill said: 'The safety and efficacy of mifepristone is backed by more than a quarter century of rigorous scientific research, FDA and regulatory review, and real-world use. This ongoing case is nothing but an extremist attempt to interfere with the FDA's regulatory authority.'
'This case has always been about ideology, not patient safety,' said Emily Wales, president and CEO of Planned Parenthood Great Plains. Meanwhile, the Trump administration's Department of Justice has taken over defence of the FDA's regulations, and its commitment to defending the current access framework remains uncertain.
The abortion pill has survived its most direct legal challenge. Whether it survives the next one will depend on courts, governments, and the enduring question of who gets to determine what medicine women can access, and under what conditions.
