Yaz Resources

Studies & Medical Journal Articles

As early as 2004, doctors and researchers were voicing their concerns about the new progestogen "drospirenone" found in Yaz and Yasmin.  In one European study, doctors and researchers associated drospirenone-containing birth control pills with an increased risk of developing blood clots. The study explicitly advises physicians against prescribing pills like Yaz and Yasmin as a first choice for women starting birth control.  J Thromb Haemost 2004; 2: 2060-2.

To see this medical journal article, click here.

Additionally, two epidemiological studies published last year in the British Medical Journal suggest that the risk of venous thromboembolism ("VTE") - blood clotting within the veins - is higher in Yasmin users than it is for users of earlier generation birth control pills containing the progestin levonogestrel.

In the first of these studies, Dr. Vlieg of the Department of Clinical Epidemiology at Leiden University Medical Center in the Netherlands found that oral contraceptives that contain the ingredient drosperinone, like Yaz and Yasmin, are associated with "a sixfold to sevenfold increased risk [of VTE] compared with non-users." BMJ 2009; 339: b2921.

To read Dr. Vlieg's study, click here.

In the second study, conducted by Dr. Lidegaard of the Gynaecological Clinic at Copenhagen University in Denmark, researchers found that the risk of VTE from pills containing drospirenone, like Yaz and Yasmin, is higher than with older birth control pills containing levonorgestrel. BMJ 2009; 339: b2890

To read Dr. Lidegaard's study, click here.

Newspaper Articles

On September 25, 2009, the New York Times published an article on Yaz and Yasmin, summarizing consumer concerns about Bayer's misleading marketing practices and mentioning the research studies associating these drugs with an increased risk of cardiovascular health problems.

The article highlights the fact that the FDA warned Bayer about its misleading television commercials for Yaz and Yasmin and also its violations of quality control procedures in its plant. These events raise questions about Bayer's approach to complying with government rules.  Additionally, the article points out that drospirenone, the progestin found in Yaz and Yasmin, may increase potassium levels in the body. High levels of potassium can cause hyperkalemia, a serious condition that can lead to heart and health problems.

To read the New York Times article, click here.