Yaz was pitched as the blockbuster birth control pill with benefits, the choice for women desperate for relief from severe PMS and acne. But now, several new independent studies have found that Yaz carries higher blood clotting risks than other leading birth control pills, leading to new scrutiny from safety regulators.
He indicated that if he had been head of the FDA in 2000 and knew what he knows now, he may not have approved the drug.
"Bayer violated its duties under FDA regulations and state law by selectively presenting data as to [blood clotting] events," Kessler said in court documents, citing studies that Bayer itself conducted but allegedly misreported to regulators. "In my opinion, had I, or a medical review officer, known these facts prior to approval, further investigation would be warranted," he wrote.
Bayer maintains that Yaz is safe. "Based on a thorough assessment of the available scientific data, Bayer believes that its drospirenone-containing products are safe and effective and have a favorable benefit-risk profile when used in accordance with U.S. product labeling," Bayer spokeswoman Rose Talarico told ABC News.
Yaz was the best-selling birth control pill in the United States for 2008 and 2009. Tens of millions of women switched to Yaz since it was launched a decade ago. ABC News investigated whether these women switched to a more potentially risky pill that, as it turns out, was never proven to treat common PMS.
Most women switched to Yaz after watching one of its commercials that suggested this pill could help with bloating and acne. "Yaz is the only birth control proven to treat the physical and emotional premenstrual symptoms that are severe enough to impact your life," claimed the ad.
Yaz contains a unique hormone called drospirenone that some experts say may trigger more blood clots than other birth control pills. Clots can cause serious breathing problems, a stroke or even death. All birth control pills come with some risk. Two to four women per 10,000 on the pill will suffer blood clots, and some will die as a result. But with Yaz, several new independent studies have put that risk two to three times higher.