The US Supreme Court has rejected a bid by an anti-abortion group that included doctors to restrict access to the abortion pill.
The justices ruled that abortion opponents lacked the legal right to sue over the federal Food and Drug Administration's (FDA) approval of the medication, mifepristone, and the FDA's subsequent actions to ease access to it.
It is the court's first decision on abortion since conservative justices overturned Roe vs Wade two years ago.
The case had threatened to restrict access to mifepristone across the country, including in states where abortion remains legal.
The ruling is a win for US President Joe Biden who is an outspoken advocate for abortion rights.
He has tried to make abortion a key point of difference between him and Donald Trump in the lead-up to the presidential election in November.
The FDA approved mifepristone more than 20 years ago and has reiterated its safety and effectiveness since.
Unanimous decision
The justices voted 9-0 to overturn a lower court's decision to roll back the FDA's steps in 2016 and 2021 that eased how mifepristone is prescribed and distributed.
Justice Brett Kavanaugh wrote for the court that "federal courts are the wrong forum for addressing the plaintiffs' concerns about FDA's actions".
He was part of the majority that overturned Roe vs Wade.
The high court is separately considering another abortion case, about whether a federal law on emergency treatment at hospitals overrides state abortion bans in rare emergency cases in which a pregnant patient's health is at serious risk.
How does the drug work?
More than 6 million people have used mifepristone since 2000 and it is used in more than 60 per cent of abortions.
Mifepristone blocks the hormone progesterone and primes the uterus to respond to the contraction-causing effect of a second drug, misoprostol.
The two-drug regimen has been used to end a pregnancy through 10 weeks gestation.
Health care providers have said that if mifepristone is no longer available or is too hard to obtain, they would switch to using only misoprostol, which is somewhat less effective in ending pregnancies.
Mr Biden's administration and drug manufacturers had warned that siding with abortion opponents in this case could undermine the FDA's drug approval process beyond the abortion context by inviting judges to second-guess the agency's scientific judgements.
The Democratic administration and New York-based Danco Laboratories, which makes mifepristone, argued that the drug is among the safest the FDA has ever approved.
Opponents argued drug was dangerous
The abortion opponents argued that the FDA's decisions in 2016 and 2021 to relax restrictions on getting the drug were unreasonable and "jeopardise women's health across the nation".
The mifepristone case began five months after the Supreme Court overturned Roe.
Abortion opponents initially won a sweeping ruling nearly a year ago from US District Judge Matthew Kacsmaryk, a Trump nominee in Texas, which would have revoked the drug's approval entirely.
The 5th US Circuit Court of Appeals left intact the FDA's initial approval of mifepristone.
But it would reverse changes regulators made in 2016 and 2021 that eased some conditions for administering the drug.
The Supreme Court put the appeals court's modified ruling on hold, then agreed to hear the case, though Justices Samuel Alito — the author of the decision overturning Roe — and Clarence Thomas would have allowed some restrictions to take effect while the case proceeded.
AP/Reuters
