The first emergency contraceptive pill that can be taken almost a week after sexual intercourse has been developed.
The existing “morning-after pill” can be taken up to three days after intercourse, but a new version, called ellaOne, still works five days afterwards, according to the Vancouver Sun. The drug is not FDA approved.
Levonorgestrel, commonly known as Plan B in the U.S., is an emergency contraceptive only effective if women take it within three days of having sex. It is available in more than 140 countries and in nearly 50 of those countries women can get it without a prescription.
Dr. Anna Glasier of the Family Planning and Well Woman Services Dean Terrace Centre in Edinburgh, Scotland, who led the Lancet study, said the explanation of why ellaOne works for two more days than Plan B may be in the way they effect ovulation.
Plan B contains synthetic progesterone and mimics how the natural hormone works, interfering with ovulation in the early stages of the egg’s development. In contrast, ellaOne delays ovulation until the egg is released from the ovary.
Experts tracked nearly 1,700 women aged 16 to 36 who received emergency contraception within three to five days of having unprotected sex. About half got Plan B while the rest got ellaOne.
In the group that got Plan B, there were 22 pregnancies. In those that got ellaOne, there were 15. In both groups, the most frequently reported side effect was a headache. The research was paid for ellaOne’s maker, HRA Pharma, which helped design the study.
Emergency contraceptive pills do not prevent against sexually transmitted diseases. [The Lancet]
