The official, who spoke on condition of anonymity, said the agency will announce that it is complying with a federal judge's order that overturned a Bush administration policy. The official was not authorized to speak publicly before the FDA announcement, expected later Wednesday.
Last month, U.S. District Judge Edward Korman ruled in a New York lawsuit that Bush administration appointees let politics, not science, drive their decision to allow over-the-counter access to these pills only for women 18 and older. Korman ordered the agency to let 17-year-olds get the medication, and separately to evaluate whether all age restrictions should be lifted.
Plan B is emergency contraception that contains a high dose of birth control drugs and will not interfere with an established pregnancy. Religious conservatives say it is the equivalent of an abortion pill because it can prevent a fertilized egg from attaching to the uterus.
The battle over access to Plan B has dragged on for the better part of a decade, through the tenures of three FDA commissioners. Among many in the medical community, it came to symbolize the decline of science at the agency. Top FDA managers refused to go along with the recommendations of scientific staff and outside advisers that the drug be made available over-the-counter with no age restrictions.
"The FDA got caught up in a saga; it got caught up in a drama," said Susan Wood, who served as the agency's top women's health official and resigned in 2005 over delays in issuing a decision. "This issue served as a clear example of the agency being taken off track, and it highlighted the problems FDA was facing in many other areas."
If taken within 72 hours of unprotected sex, Plan B can reduce a woman's chances of pregnancy by as much as 89 percent. It contains a high dose of birth control drugs and works by preventing ovulation, fertilization, or the implantation of a fertilized egg in the uterus.
If a woman already has become pregnant, Plan B has no effect.
However, social conservatives say that since it can prevent the implantation of a fertilized egg, Plan B is the equivalent of an abortion pill.
The treatment consists of two pills and sells for about $35 to $60. Women must ask for Plan B at the pharmacy counter, and show identification with their date of birth. The drug is made by a subsidiary of Teva Pharmaceutical Industries, an Israeli company. It does not prevent sexually transmitted infections, including HIV/AIDS.
Supporters of broader access argued that Plan B was safe and effective in preventing unwanted pregnancy, and thus could help reduce the number of abortions.
Opponents, including prominent conservatives, countered that it would encourage promiscuity and might even become a tool for criminals running prostitution rings, as well as for sexual predators.
Early in the Bush administration, more than 60 organizations petitioned the FDA to allow sales without prescriptions. But according to court documents, the issue quickly became politicized.
In 2003, a panel of outside advisers voted 23 to 4 to recommend over-the-counter sales without age restrictions. But top FDA officials told their subordinates that no approval could be issued at the time, and the decision would be made at a higher level. That's considered highly unusual, since the FDA usually has the last word on drug decisions.
In his ruling, Judge Korman said that FDA staffers were told the White House had been involved in the decision on Plan B. The government said in court papers that politics played no role.
In 2005, the Center for Reproductive Rights and other organizations sued in federal court to force an FDA decision.
The following year, the FDA allowed Plan B to be sold without a prescription to adults. But the controversy raged on over access for teens.