USA Today: What does the Mifepristone case mean for Plan B? The difference between the two explained.

Emergency contraception is not the same thing as the abortion pill, but these medications are often confused. While both involve reproductive health, emergency contraception ‒ often called Plan B ‒ is meant to stop a pregnancy from happening, and the abortion pill mifepristone ends an existing pregnancy, medical experts say.

Delineating the two medications is more important than ever as the Supreme Court heard arguments Tuesday on a case that could sharply limit access to mifepristone and diminish the independence of the Food and Drug Administration.

An anti-abortion organization is challenging mifepristone's FDA approval, claiming the agency bypassed standard protocols to bring the medication to market.

Abortion advocates say the pill should not lose its FDA approval, citing decades of safety and efficacy in patients across the nation.

Mifepristone remains FDA-approved at the moment and available to many Americans from reproductive health clinics or telemedicine services, although full access to the pill is restricted in 15 states. The "Plan B" pill is legal in all 50 states without age restrictions.

The court's decision in the mifepristone case, expected this summer, could have a long-term impact on the FDA’s ability to make decisions about the safety of all drugs. This means that while neither pill's approval changes today, there could be ramifications for all medications and the future of reproductive health systems nationally.

"Regardless of the result, it will not have an immediate impact on emergency contraception," Dana Singiser, co-founder of the Contraceptive Access Initiative, said of Tuesday's case.