The Food and Drug Administration (FDA) has approved the use of Plan B One-Step without a prescription for all women.

The FDA announced on Thursday that it would allow all women with child-bearing potential to purchase the emergency contraceptive over-the-counter without any age or point-of-sale barriers.

Plan B-One Step (levonorgestrel) is a form of the "morning-after pill," a type of emergency contraception that drastically reduces the chance of pregnancy after a woman has engaged in unprotected sex. There are currently three types of morning-after pills for sale in the U.S.: Plan B One-Step, Plan B, and ella. Plan B is currently available for women 17 and older over the counter, and requires a prescription for those under the age limit. Ella requires a prescription regardless of age.

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Plan B One-Step works best when it is taken within three days after sexual intercourse. It will not stop a pregnancy if a woman is already pregnant, and no evidence shows that it will harm a fetus that already exists.

"Over-the-counter access to emergency contraceptive products has the potential to further decrease the rate of unintended pregnancies in the United States," said Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, said in a press release.

The new approval was years in the making.

In 2011, the FDA was preparing to allow over-the-counter sales of the morning-after pill without age restrictions, citing research of the pill's safety and effectiveness. After, Health and Human Services Secretary Kathleen Sebelius rejected the move. Her decision went against her scientific advisory panel. President Barack Obama said at the time that he supported the decision.

"As the father of two daughters, I think it is important for us to make sure that we apply some common sense to various rules when it comes to over-the-counter medicine," Obama said previously.

On April 5, 2013 U.S. District Judge Edward Korman ruled that emergency contraception should be available to women of all ages, calling the FDA's age restrictions "arbitrary, capricious and unreasonable." He gave the FDA 30 days to comply.

However, Plan B One-Step had withdrawn its all ages, over-the-counter approval request, and resubmitted an application asking for the product to be approved for those 15 and older. In late April, the FDA only approved the non-prescription use of Plan B One-Step for that age group. The agency said the products would be in stores with onsite pharmacies, although they could be sold after the pharmacy closed. In addition to theft-deterrent tags, age verification checks were required at the counter before purchase.

Critics were outraged that the age barrier still remained, and pointed out that requiring identification would make it more difficult for some women to access the product.

"Lowering the age restriction to 15 for over-the-counter access to Plan B One-Step may reduce delays for some young women -- but it does nothing to address the significant barriers that far too many women of all ages will still find if they arrive at the drugstore without identification or after the pharmacy gates have been closed for the night or weekend," Nancy Northup, president and CEO of the Center for Reproductive Rights, said in a press release. "These are daunting and sometimes insurmountable hoops women are forced to jump through in time-sensitive circumstances, and we will continue our battle in court to remove these arbitrary restrictions on emergency contraception for all women."

The Obama administration said itwould appeal Korman's decision allowing women of all ages to have access to the morning-after pill.

Korman said on May 10 that he refused to suspend his initial ruling.

On June 10, the federal government said it would comply with Korman's decision and withdraw the appeal. A federal judge approved the government's proposal to remove the age restrictions on June 13, paving the way for the FDA to fast-track today's approval.