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 Jessica Ellsworth, representing mifepristone manufacturer Danco Labs, now speaking, Justice Clarence Thomas pressed her on the the 19th-century Comstock Act and why that legislation doesn't bar the use-by-mail of the abortion pill.

Ellsworth responded that Comstock has long not been enforced and that she believes this legal challenge is not an opportunity for the justices to "opine" on Comstock's reach.

The federal government previously said in Tuesday's hearing that they do not believe Comstock's requirements are within the FDA's purview as it regulates drugs.

Ellsworth seemed to echo that during her own presentation and questioning, warning that the justices "should think hard about the mischief" that could be created by requiring FDA regulatory approval to be restricted by provisions beyond safety.

-ABC News' Adam Carlson

Three women are participating in Tuesday's arguments.

Elizabeth Prelogar, the solicitor general at the Department of Justice, is arguing on behalf of the federal government.

Jessica Ellsworth is representing Danco Labs, the manufacturer of mifepristone.

Erin M. Hawley is counsel speaking for the Alliance for Hippocratic Medicine, a group of anti-abortion medical organizations that brought the challenge against the FDA and mifepristone.

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