Oral arguments have begun over the abortion pill mifepristone and whether the FDA lawfully relaxed restrictions on the drug to make it easier to access to end a pregnancy.

Solicitor General Elizabeth Prelogar will be the first to give an opening statement.

With arguments set to begin shortly, there are large competing demonstrations outside the building.

Small groups of pro-abortion rights demonstrators were staging sit-ins on sidewalks and roadways.

There is a heavy police presence and Capitol Police are conducting some arrests.

The lead plaintiff, the Alliance for Hippocratic Medicine, had initially challenged the FDA’s approval of mifepristone.

But the matter before the high court now is more narrow -- whether the FDA's subsequent regulatory decisions about the drug, in 2016 and 2021, were sound.

In court filings, the Alliance Defending Freedom, a Christian conservative legal advocacy representing the plaintiffs, has claimed mifepristone is not safe and that the FDA didn't study it closely enough before it was approved.

The group also argued that the FDA’s decisions in 2016, lowering the recommended dosage and extending the use from seven weeks through 10 weeks of pregnancy, and in 2021, which permanently lifted the restriction on requiring abortion pills to be dispensed in-person, were unsound.

In January 2022, the FDA went further by allowing retail pharmacies to provide the drug too, either by mail or in person, so long as they meet certain requirements, which the plaintiffs claim violate federal laws that prohibit the distribution of chemical abortion drugs by mail.

The FDA rejects the claims, arguing that mifepristone is safe when used as indicated and directed, and that the pill went through a thorough and comprehensive review before being approved.

Mifepristone is a drug typically used in combination with another drug, misoprostol, to induce an abortion or to help manage an early miscarriage.

The medication works by blocking progesterone, a hormone that the body needs to continue a pregnancy.

This causes the uterine lining to stop thickening and to break down, detaching the embryo. The second drug, misoprostol, taken 24 to 48 hours later, causes the uterus to contract and dilates the cervix, which will expel the embryo.

The FDA authorized mifepristone for medication abortion in September 2000 for up to seven weeks' gestation, which was then in 2016.

However, the World Health Organization says the two drug-regiment can be taken up until the 12-week mark of pregnancy.

Justice Ketanji Brown Jackson asked Erin Hawley, the attorney for Alliance Defending Freedom -- the group representing the plaintiffs -- if a nationwide reversal of the FDA's approval of mifepristone is needed and if the court can simply rule that doctors do not need to prescribe the pill if they have conscience objections.

"Do we have to entertain your argument that no one in the world can have this drug in order to protect your client?" the justice asked.

Hawley argued that given the "emergency nature," it is "impracticable" to not have a broader ban or block on access to the pill.

Justice Neil Gorsuch echoed Jackson's question and asked if it is enough for the court to rule on behalf of the plaintiffs not being required to prescribe the pill and why the court has to consider a universal injunction.