A warning for women who use the birth control patch.
Preliminary findings from a new study show these women face double the risk of developing blood clots than those on the pill.
Birth control maker ortho paid for two studies comparing patches to pills.
The company says the first study found no increased risk of clots among patch users.
However, the second suggested a two fold increased risk of clots in the legs and lungs.
Doctors say the patch gives off more estrogen than birth control pills which can lead to blood clots.
Ortho says despite the new research the risk of clots remains rare.
And the FDA says it will not take immediate action on the preliminary findings.
However, the government agency believes patch users should talk to their doctor.