Teva Pharmaceuticals manufactures Ocella and received approval by the FDA in 2008 to use Ocella as a contraceptive. It contains a mixture of drosperinone and estrogen. Drosperinone has been identified as an ingredient that poses significant risk to women taking the drug. It has been shown by multiple studies to greatly increase the chance of developing blood clots. These blood clots have the potential to cause heart attack, stroke, and pulmonary embolisms.