On Thursday, the Food and Drug Administration approved the first over-the-counter birth control pill in the United States. Federal regulators approved Opill, made by the consumer health giant Perrigo, as a nonprescription oral pill used to prevent pregnancy. The decision comes at a moment when challenges to reproductive rights have created a climate of uncertainty and raised concerns about the availability of essential health care.

“This is historic and transformative for reproductive rights without having to go to a physician, which presents a barrier to many people,” according to Julie Maslowsky, an associate professor at the University of Illinois Chicago School of Public Health. She was a scientific consultant for HRA Pharma, a subsidiary of Perrigo that submitted the application to the FDA for approval.

Maslowsky said an over-the-counter pill will have a positive impact on marginalized populations, including people with low incomes who live in very rural areas with few health care options, and so have the highest rate of unplanned pregnancy. “This will absolutely increase options and allow them to control their reproductive health,” Maslowsky said.

Here’s what else to know about the pill:

When will the over-the-counter pill be available?

Opill is expected to be available over the counter in stores and online beginning in January or February, Perrigo said in a statement. The FDA decision does not apply to other forms of the birth control pill.

How much will Opill cost?

Pricing has not been set, but Frédérique Welgryn, Perrigo’s global vice president for women’s health, said in a statement that the pill will be “accessible and affordable to women and people of all ages.” The company expects to release pricing information in the fall.

Questions loom about health insurance coverage. Sabrina Corlette, a research professor at Georgetown University’s McCourt School of Public Policy, said that under the Affordable Care Act, health insurance plans are required to cover the cost of prescribed birth control pills. But over-the-counter medications like oral contraception don’t necessarily fall under the umbrella of coverage.

“So the coverage issues are still a little murky,” Corlette said. “They haven’t issued any clear direction to health plans yet.”

Where can you buy Opill?

The FDA said the pill will be available in pharmacies, convenience stores, grocery stores and online.

How old do you have to be to buy Opill?

There is no age limit, “and that’s a big victory,” Maslowsky said. She compares Opill’s approval to when the emergency contraceptive pill Plan B became available over the counter. Plan B was restricted by age, and that meant people needed to show an ID to buy it.

“We were afraid that might be repeated, because it impacted not only adolescents, but also other people who didn’t have an ID or were afraid to ask for it because it was locked [away],” Maslowsky said.

Is Opill different from other birth control pills?

Many prescription birth control pills combine synthetic forms of the hormones estrogen and progesterone. This impedes pregnancy in a few ways, including thickening the cervical mucus, making it difficult for an egg to be fertilized by sperm; thinning the uterine lining so that it’s harder for a fertilized egg to implant and grow; and suppressing ovulation.

Opill, which is sometimes called a mini pill, contains only progestin, the synthetic form of progesterone. While both combination and progesterone-only birth control pills are considered safe by health experts, a progestin-only pill has even fewer side effects.

What are the side effects of Opill?

Health experts tout this form of birth control as being low risk for side effects.

“A progesterone-only pill is safe for virtually everybody,” said Colleen Denny, an associate professor in the department of obstetrics and gynecology and director of family planning at NYU Langone Hospital. “There is really no way to hurt yourself with a progesterone-only pill.”

Denny added that if there are side effects, they tend to be mild, with the most common being more spotting during a person’s period, “which is not a dangerous thing,” she said.

Will Opill be legally available everywhere in the U.S.?

The FDA approval grants authority for Opill to be sold over the counter in retail stores across the United States, including in states where abortion has been banned or significantly limited. But Jack Hoadley, a research professor emeritus at Georgetown’s McCourt School of Public Policy, said a pharmacy chain could decide to not sell it for fear of the politics surrounding reproductive medicine. For example, some pharmacy chains decided to not sell mifepristone, which is used in medication abortions, after being pressured by antiabortion advocates.

“We saw this with mifepristone, but I’m not sure the politics on this one is anywhere near the same as that drug,” Hoadley said.