A birth-control pill that may eliminate a woman's monthly menstrual cycle has won US approval for use.
Lybrel, made by drugmaker Wyeth, is meant to be taken every day to indefinitely stop monthly menstrual bleeding and prevent pregnancy.
It contains two hormones widely used in other oral contraceptives and should be available in US pharmacies in July.
Traditional birth control pills are usually taken for 21 days followed by seven days of placebo pills or no pills, which allows a period of bleeding to occur. For years, some women have been stopping their periods by taking birth control constantly without the break.
Lybrel is the first, however, that is approved for that use. It takes time, however, for periods to be suppressed, and most women will have intermittent bleeding during the first year of use, the US Food and Drug Administration said.
"The convenience of having no scheduled menstruation should be weighed against the inconvenience of unscheduled bleeding or spotting," the licensing authority said.