The new labeling will apply to Bayer's Yaz, its predecessor Yasmin and similar drugs that have the manmade hormone called drospirenone, which mimics the naturally occurring female hormone progesterone.
The /*Food and Drug Administration*/ says the new labels will say that some studies have found as high as a threefold increase in the risk of blood clots in women taking pills containing drospirenone.
The risk of blood clots with either group of drugs is still very rare.
The Associated Press contributed to this report.
