Pharmaceutical scientists are developing a pill that is taken by women once a month and is capable of preventing pregnancy, the BBC reports.

Once taken, the pill stays in the woman's stomach for a week, slowly releasing pregnancy-preventing hormones. This means that it would be much more effective than contraceptives on the market.

Developed by a team of doctors funded by the Bill and Melinda Gates Charitable Foundation, the pill has already been tested on pigs and experts believe it will be available in pharmacies within a few years.

Scientists believe it will bring relief to women who take contraceptives, but should be constantly worried whether they have forgotten their daily dose. Its efficiency is about 99%.

Studies of contraceptive use show that about half of women who take contraceptives are more often at risk of tolerance to the active substance that prevents pregnancy.