EllaOne: New Morning-After Pill is Effective Up to 5 Days

Jan 29, 2010
A novel emergency contraception pill can be used up to 120 hours to prevent unwanted pregnancy, scientists say.

EllaOne, a new morning after-pill that was released in November contains ulipristal acetate, a selective progesterone receptor modulator. Ulipristal works by suppressing ovulation and may also prevent the growth of the endometrium, which makes implantation impossible.

The traditional emergency contraception or Plan B contains levonorgestrel, synthetic progesterone, which should be taken 24 hours after unprotected sex. Plan B imitates how the natural hormones work, suppressing ovulation in the early phase of development, while EllaOne works by preventing ovulation until the egg is released from the ovary.The morning-after pill is available in most pharmacies and clinics, while EllaOne is sold in Europe only with doctor's prescription.

The study that included 1,700 women aged between 16 and 36, compared the effectiveness of Plan B birth control and novel contraceptive EllaOne. The participants took two different types of emergency contraceptive pills within three to five days after unprotected intercourse.

The results of the study showed that among women, who used traditional emergency contraception, 22 percent resulted in pregnancies. Those, who took EllaOne pill, had 15 percent of pregnancies. Women, who took the EllaOne five days after unprotected sex, had as much as 50 percent success rate.

Scientists say that women taking ulipristal may report mild to moderate side effects, such as headache, nausea and abdominal pain, which resolved on itself. The drug also can speed up or delay the next period for a woman.

Further research is needed before the new drug can will be available for over-the-counter use.

The study was published in the British medical journal, Lancet.