If the F.D.A. approves an over-the-counter version, it will be effectively saying that women with underlying health risks who choose that option will have to do their own research on how the birth-control pill would interact with their condition and any other medications they are taking.

Reproductive-rights activists in the United States view an over-the-counter birth-control pill as an easy and effective tool for rural, poor and historically marginalized communities to avoid unwanted pregnancies — reducing their barriers to health care and lowering the abortion rate along the way.

At least two drug companies want to apply to the F.D.A. to make the switch to an over-the-counter version, and have been in communication with the agency about their plans. But after years of preliminary trials to clear the agency’s research and consumer-testing hurdles, neither has reached the stage of applying yet.

The F.D.A. defenders say that by asking many questions and demanding rigorous testing, the agency is being prudent about assessing the potential health risks of making the pill available without a prescription.

But frustrated supporters of the switch are critical of the agency’s prolonged pre-application process — which at certain points requires F.D.A. permission to advance to the next stage. Some of them see the process as an obstacle to the advancement of reproductive rights, as well as a case study of the cost when the F.D.A. takes an overly cautious approach. (The agency has also been criticized in other drug-approval cases of moving too quickly, as when it fast-tracked approval of a controversial Alzheimer’s drug earlier this year.)