The case could affect not just abortion access but oversight of the drug industry and the authority of federal agencies. The court hears arguments Tuesday.
CVS will start filling prescriptions for mifepristone in Massachusetts and Rhode Island. Walgreens will start in New York, Pennsylvania, Massachusetts, California and Illinois.
The study looks at 6,000 patients who got abortion pills after an online appointment. It found that 99.7% of those abortions were not followed by any serious adverse events.
A research paper that raises questions about the safety of abortion has been retracted. The research is cited in a federal judge's ruling about the abortion pill mifepristone.
The court's action sets up a collision between the Food and Drug Administration's 23-year study and supervision of mifepristone, and the circumstances under which it can be prescribed.
A federal appeals court would restrict the use of mifepristone, a pill used in medication abortions. But previous action by the Supreme Court means the status quo holds for now.
The latest Gallup poll also finds increased political polarization. Some 60% of Democrats said abortion should be legal under any circumstances, compared with 8% of Republicans.
While a Supreme Court order continues to ensure the drug is still widely available, the issue returned Wednesday to the Fifth Circuit Court of Appeals as lawyers for both sides urged the court to act.