Bayer's birth control drug Yasmin (sometimes referred to as "Yaz") and its generic version Ocella contain drospirenone, which might cause an increase in potassium levels which in turn might cause heart failure, blot clots, strokes or even death.

This is a broad investigation and pending multiple similar actions against Bayer AG for its manufacture of the Yasmin and Yaz birth control bill and against Barr Laboratories Inc. for its manufacture and sale of Ocella, the generic version of Yaz and Yasmin.

Yasmin, Yaz and Ocella are oral birth control bills. Each birth control pill contains ethinyl estradiol the same estrogenic compound that has been used in birth control pills since the 1970s. What is different with Yaz, Yasmin and Ocella is the progestin used in these birth control bills. Postegestin is a synthetic steroid hormone used to suppress ovulation. Yasmin and Yaz both contain drospirenone, a "fourth generation" progestin. No other birth control pills contain drospirenone, except for a recently approved generic version of Yasmin and Yaz, called Ocella.

Drospirenone causes an increase in potassium levels in the blood. The FDA has warned Bayer that "increased serum potassium can be dangerous." Excess serum potassium can lead to a condition known as hyperkalemia. Hyperkalemia can cause heart rhythm disturbances, such as extrasystolies, pauses or bradycardia. Hyperkalemia, left untreated disrupts the normal heart rhythms, the flow of the blood through the heart can be slowed to the point that it permits blood clots to form. Blood clots in the heart can then lead to heart attacks, or break off and travel to the lungs where they can cause pulmonary embolus, or travel to the brain causing stroke.

In addition, Yasmin and Yaz are marketed to reduce water retention and bloating often associated with premenstrual dysphoric disorder (PMDD). However, too much loss of fluids can lead to dehydration, which also increases the risk of blood clots. If Yasmin or Yaz lead to excessive loss of fluids resulting in dehydration, women using these products can be at an increased risk of blood clots.

From the first quarter of 2004 through the third quarter of 2008, well over 50 reports of death among users of Yasmin and Yaz have been filed with FDA. These include numerous deaths with reported cardiac arrhythmia, cardiac arrest, intracardiac thrombus (blood clots in the heart), pulmonary embolism (blood clot in the lungs) and stroke in women in their childbearing years. Some of the deaths occurred in women as young as 17 years old.