The first four-phase oral contraceptive has been approved by the Food and Drug Administration in the US.
Natazia, manufactured by Bayer Healthcare, combine female hormones estrogen and progestin in doses that adjust four times during a woman’s menstrual cycle.
It is the first birth control product to use four-phase dosing, the FDA said.
The most common side effects reported in clinical trials included irregular bleeding, headaches, nausea and vomiting.
German conglomerate Bayer already sells the birth control pills Yaz and Yasmin. The drugs were the company’s top-selling pharmaceutical franchise last year, with combined sales of $1.64 billion.
Copyright Press Association 2010