Attorney Erin Hawley, representing the anti-abortion Alliance for Hippocratic Medicine that is challenging mifepristone, has begun her presentation to the justices.

Hawley is echoing the alliance's attacks on the drug's use and regulation by the FDA, contending that it creates harm to women and burdens doctors who must then care for such patients who use mifepristone.

Hawley also invoked an "intolerable" choice that is created by the widespread use of mifepristone -- if an anti-abortion doctor must consider treating abortion patients in an emergency situation or not.

-ABC News' Adam Carlson

Jessica Ellsworth, the attorney for Danco Labs, was asked by Justice Ketanji Brown Jackson if she was concerned about the prospect of judges parsing medical and scientific studies without specialized knowledge.

"I think we have significant concerns about that," Ellsworth said, noting the pharmaceutical industry submitted briefs to the court expressing that worry.

She went on to state that U.S. District Judge Matthew Kacsmaryk, who initially ruled to suspend mifepristone's approval, relied on studies that "were not in the administrative record" and never would have been.

"They have since been retracted for lack of scientific rigor and misleading presentations of data," she said.

Sage Publishing said it issued the retractions from the journal Health Services Research and Managerial Epidemiology because of methodology issues and conflicts of interest, ABC News previously reported.

Justice Samuel Alito asked Jessica Ellsworth, the attorney representing Danco Laboratories, if she thinks the FDA should have continued requiring prescribers to report non-fatal complications, known as “adverse events" of mifepristone.

Ellsworth argued the FDA made that decision after 15 years of data that established mifepristone was safe. She also rejected Alito's question asking if the FDA was "infallible".

Justice Kentanji Brown Jackson asked if the defendants had concerns about judges "parsing medical and scientific studies" and Ellsworth said there were concerns.

Jessica Ellsworth, who is representing the manufacturer of Mifeprex (the brand name of mifepristone), similarly criticized the plaintiff's claim of injury and their interpretation of the law.

She said the respondent's view is "so inflexible it would upend not only Mifeprex but virtually every drug approval and [risk and mitigation] modification the FDA has made for decades."

With the hearing wrapped, after about two hours of arguments, the Supreme Court appeared highly skeptical of the challenge to the mifepristone regulations brought by a group of anti-abortion doctors -- suggesting recent steps to ease access to the medication used by millions of American women may be allowed to stand.

At the heart of the case are steps taken by the FDA in 2016 and 2021 to roll back safety measures around the pill, which was first approved for use in 2000.

The plaintiff doctors -- who do not prescribe mifepristone, use mifepristone or otherwise perform abortions -- claim that wider availability of the drug was authorized improperly and has adversely impacted them, forcing them to care for women in emergency rooms suffering complications from the pill, often in violation of their conscience.

While conservative-leaning Justices Samuel Alito and Clarence Thomas were the most sympathetic to the legal challenges, for the most part, the court on Tuesday steered clear of openly second-guessing FDA’s scientific analysis of mifepristone.

A majority of the justices, across the ideological spectrum, expressed doubt during the arguments that the doctors had sufficiently demonstrated legal standing that they had been directly harmed by the FDA’s mifepristone rule changes.

“It makes sense for individual doctors to seek a [conscience] exemption but they already have that,” said liberal-leaning Justice Ketanji Brown Jackson. “What they are asking for here is -- in order to prevent them from ever having to do these kinds of procedures -- that everyone else should be prevented from getting access to that medication. How is that not overbroad?”

That view was echoed by conservative-leaning Justice Neil Gorsuch.

Erin Hawley, the attorney for the doctors, was repeatedly pressed to provide specific examples or testimony from a physician who had been forced to violate his or her conscience in treating a mifepristone patient but she could not do so.

Solicitor General Elizabeth Prelogar, defending the FDA on behalf of the Biden administration, warned of "profound harm" for women and for drug companies working with the FDA should the lower court's restrictions on mifepristone remain.

-ABC News' Lalee Ibssa and Devin Dwyer