The U.S. Food and Drug Administration has approved the first over-the-counter birth control pill, allowing Americans to buy a daily oral contraceptive without a prescription.

Opill, the progestin-only pill from drugmaker Perrigo, will provide an option for obtaining oral contraceptives without needing to first see a health care provider, in hopes of reducing barriers to access, according to the FDA's news release, which notes that almost half of the 6.1 million pregnancies in the U.S. each year are unintended.

"Today's approval marks the first time a nonprescription daily oral contraceptive will be an available option for millions of people in the United States," Dr. Patrizia Cavazzoni, director of the FDA's Center for Drug Evaluation and Research, said in a news release Thursday morning. "When used as directed, daily oral contraception is safe and is expected to be more effective than currently available nonprescription contraceptive methods in preventing unintended pregnancy."

In a press briefing following the FDA's decision, Frederique Welgryn, Perrigo's global vice president of women's health, called the approval "a historic moment and a revolutionary change in contraceptive access and reproductive health."

How does Opill work? 

Opill is made up of norgestrel, a kind of "progestin-only" birth control pill that was first approved as safe and effective to be prescribed by doctors in the 1970s. This is different from other birth control pills that are largely prescribed today, which are newer "combined" formulations that also use estrogen.

Hormone-based pills, which have all required a prescription until now, have long been the most common form of birth control in the U.S., the Associated Press reports. Tens of millions of women have used them since the first pills came on the market in the 1960s. 

Is Opill safe?

The FDA says Opill is "safe and effective" when used properly. The guidelines include taking the pill at the same time every day; not using it along with another hormonal birth control product, including IUDs (intra-uterine devices); and avoiding medications that interact with it, which could decrease its efficacy.

"Opill should not be used by those who have or have ever had breast cancer," the FDA's release adds. "Consumers who have any other form of cancer should ask a doctor before use."

According to the FDA, the most common side effects of Opill include: 

• Irregular bleeding
• Headaches
• Dizziness
• Nausea
• Increased appetite
• Abdominal pain
• Cramps or bloating

When will Opill be available? 

The company says it expects the pills to go on sale at major retailers early next year. There will be no age restrictions on sales.

The FDA says the drug will be available in drug stores, convenience stores and grocery stores, as well as online.

How much will Opill cost?

Welgryn did not provide over-the-counter pricing information in Thursday's briefing, but said it was Perigo's mission to make it "affordable and accessible to people who need it."

While over-the-counter medicines are generally cheaper than prescription drugs, they aren't typically covered by insurance.

Welgryn said the company is hoping to change that approach by insurers, but did not have an estimated timeline for coverage, noting that it will "take time."

Alex Tin and the Associated Press contributed to this report.

In:
• Food and Drug Administration
• Birth Control