Justice Elena Kagan pressed Solicitor General Elizabeth Prelogar on the "arresting" statement from the government that this case marks the first time any court has restricted access to an FDA-approved drug.

"That is still to our knowledge the only time a court has done that," Prelogar responded.

"We have seen a disturbing trend of courts sometimes also overriding FDA's judgment to try to grant greater access to drugs and that overrides FDA expert judgment about what's necessary to ensure safe use," she continued. "And no matter which direction you come at it from we, on behalf of FDA, think that courts have no business making those judgments."

Solicitor General Elizabeth Prelogar suggested that the anti-abortion plaintiffs were seeking a sweeping ruling to reverse the FDA's approval of the abortion medication mifepristone because of their personal conscience views.

Prelogar was agreeing with Justice Ketanji Brown Jackson, who raised that idea as she called it a "mismatch" between the issues brought by the plaintiffs and what they are asking the court.

"The obvious common sense remedy would be to provide them with an exemption that they do not have to participate in this procedure and you say federal law already gives them that," Jackson said.

Justice Samuel Alito said the plaintiffs argued in court filings that studies have shown after the 2021 change from the FDA that allowed mifepristone to be mailed that there was an increase in emergency room visits.

He asked Solicitor General Elizabeth Prelogar if the FDA's response -- that there were not increases in side effects from the drug -- was proper.

Preolgar said this was a reasoned explanation from the FDA and the agency acknowledged that while some studies have shown the availability of abortion pills by mail led to more ER visits, this did not equate to "more serious adverse effects."

"Many might go because they are experiencing heavy bleeding which mimics a miscarriage and they need to know whether or not they are having a complication," she said.

Being cited in the arguments is the Comstock Act, a 151-year-old law under which it's illegal to use carriers such as the United States Postal Service to mail "obscene" materials such as drugs that induce abortions.

The Alliance for Hippocratic Medicine has said the FDA's decision to allow patients to receive mifepristone by mail instead of in person from certified health providers specifically violates the Comstock Act.

Solicitor General Elizabeth Prelogar, pressed by Justice Samuel Alito on why the FDA didn't consider the application of the Comstock provisions, said she did not think it fell under the FDA's "lane."

"And we don't think it means what respondents suggested," Prelogar said of the law.

Read more about the Comstock Act here.

Erin Hawley, the attorney for Alliance Defending Freedom representing the plaintiffs, said they are "harmed" without an injunction of mifepristone because it may require them to treat people experiencing abortion complications and "take an unborn life."

Justice Ketanji Brown Jackson asked Hawley asked how often would it be that the plaintiffs have to complete the procedure "in the way that you are describing?"

Hawley said plaintiffs have treated people experiencing abortion complications "dozens of times" and even said treatment may require "scraping out a uterus". However, she did not provide specific numbers.