By year's end, U.S. women will have two types of emergency contraceptive pills to choose from.
Studies show that both of them effectively prevent pregnancy after contraceptive failure or unprotected sex, but two major differences distinguish them: Only one is available without a prescription. The other is effective longer.
The Food and Drug Administration approved Ella, which contains a compound called ulipristal, in August. Watson Pharmaceuticals says it will launch Ella before the end of the year.
Its competitors: Plan B One-Step and Next Choice, which contain levonorgestrol. The original Plan B, two pills taken 12 hours apart, won FDA approval in 1999. Last year, Teva Pharmaceuticals introduced Plan B One-Step, a single pill, and Watson introduced Next Choice, a generic version of the original two-step Plan B.
Whether having two types of emergency contraceptive pills will reduce the proportion of U.S. pregnancies that are unplanned, which now stands at about one-half, remains to be seen.
"We do not believe technology holds all the answers, but having two types of safe and effective emergency contraception will increase the likelihood that a woman can access a product that works for her situation," a coalition of 20 women's health groups, including the American College of Obstetricians and Gynecologists, wrote in a June letter to the FDA.
Still, Watson spokesman Charlie Mayr says that "one of the problems is that a lot of women don't know that emergency contraceptives exist."
That worries James Trussell, head of Princeton's Office of Population Research. Trussell founded and has maintained the Emergency Contraception web site (ec.princeton.edu) since 1994.
Despite the health groups' letter to the FDA in support of Ella's approval, Trussell says, "you can't depend on doctors to spread the word about emergency contraception. My suspicion is it's fallen off the radar for many, because they know that women are going directly to the pharmacist for it."
But that's one of Plan B's advantages, says Amy Niemann, vice president and general manager for Teva Women's Health. Plan B was first available only by prescription, but four years ago the FDA OK'd over-the-counter sales to consumers age 18 and over (the FDA lowered the cutoff by a year in 2009).
"Quick and easy access to emergency contraception is really important to women getting it," she says.
The best way to prevent an unintended pregnancy is to use a primary contraceptive method -- birth control pill, condom -- consistently, Niemann says. If that fails, she says, get Plan B at a pharmacy as soon as possible. If more than three days have passed, Niemann says, use Ella.
Explore further: Drug research and development more efficient than expected