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Yaz Side Effects

Common side effects of Yaz include headache, nausea, breast tenderness, vaginal bleeding between periods and menstrual irregularities. These side effects are generally mild. Rare but serious side effects of Yaz include increased risks of life-threatening blood clots, high blood pressure, gallbladder problems, liver tumors and breast cancer.

With its chic marketing and catchy name, the Yaz birth control pill was introduced in 2006 and quickly became the most popular and best-selling oral contraceptive in the United States. But as quickly as the drug’s popularity skyrocketed, it plummeted amid concerns that it raises the risks of deadly side effects more than older contraceptive pills.

Studies from as early as 2006 have documented the side effects associated with Yaz.

Side effects of Yaz include:
  • Serious blood clots
  • Higher than normal potassium levels in blood
  • Breast cancer
  • Reproductive organ cancer
  • Liver disease
  • High blood pressure
  • Gallbladder disease

Some side effects, such as irregular bleeding, nausea, breast tenderness and headache, are usually mild and tend to go away with time. Others, such as blood clots, stroke, heart attack and gallbladder disease, are more serious and can lead to death.

Additionally, women at high risk for blot clots should also avoid Yaz, including those with a history of blots clots, stroke, or heart attack, those with uncontrolled blood pressure, and those with migraine headaches with aura.

Common Side Effects

According to the package insert, the most common Yaz side effects are headache, nausea, breast tenderness, and spotting or bleeding between menstrual periods. In general, these issues, particularly nausea and vomiting, should lessen within the first three months of taking the drug.

In contraception clinical trials that involved 1,056 women, about 16 women stopped taking the drug because of headaches or migraines, and another 10 women stopped the medication because of nausea and vomiting. About a dozen out of 536 women quit taking the pill during acne clinical trials because of prolonged, excessive or abnormal menstrual bleeding.

Nearly 12 percent of women who took the drug during clinical trials for PMDD dropped out because of the same side effects plus fatigue, breast tenderness, depression and irritability.

Other less serious side effects Yaz include acne, less sexual desire, bloating or fluid retention, blotchy darkening of the skin, high blood sugar, high fat levels in the blood, problems tolerating contact lenses, and weight changes.

Blood Clot Risks

Studies show drospirenone, an active ingredient in Yaz, may significantly increase the chances of developing venous thromboembolic events (VTE), or blood clots. Results have varied with some studies showing no additional risk, while others have shown up to a three-fold higher risk . However, the risk of developing a blood clot while taking birth control pills is generally increased in women who are obese, smoke cigarettes or are older than 35. Blood clots can lead to heart attacks, strokes and pulmonary embolisms, all of which can be deadly.

Illustration of blood clot.
According to the Yaz prescribing information, problems caused by a blood clot, such as heart attack or stroke, can be deadly or permanently disabling.

At least five large studies conducted since 2009 have shown that drospirenone not only heightens the risk of blood clots, but also it does so more than older forms of progesterone. A study by the U.S. Food and Drug Administration, for example, showed a 74 percent increased risk in Yaz users when compared to users of other oral contraceptives.

Bayer, the drug’s maker, funded the only two major studies that disprove the blood clot connection. In 2012, the FDA required an updated warning on the drug’s label to reflect the blood clot risk.

Specifically, the birth control is linked to deep vein thrombosis (DVT), a blood clot that develops in the deep veins of the body. When a clot forms in the deep veins of the legs, it is often painful and causes the legs to swell.

Once a DVT forms, the clot can easily break off and travel through the body. Blood clots that travel to the heart, brain or lungs can cause heart attack, stroke, paralysis and death.

Seemingly healthy females, some as young as 14 and 15, have reportedly died from Yaz-related DVT. Countless others have allegedly been injured.
Bayer refutes the claims. It says the risks of taking Yaz are no different than any other oral contraceptive.

However, in 2015, a study published in BMJ looked at nearly 11,000 cases of blood clots in women ages 15 to 49 and found the risk of blood clots associated with birth control pills was higher for newer oral contraceptives like Yaz compared to older drugs.

Bayer has agreed to pay more than $2 billion to settle claims in more than 10,000 Yaz lawsuits over blood clot injuries caused by the drug.


Yaz, when used with certain other drugs may increase the risk of high potassium levels, a condition called hyperkalemia. The risk is fairly low. But federal regulators did require Bayer to include a warning on Yaz’s package insert and labeling.

Drospirenone found in Yaz affects potassium levels by interfering with the normal functioning of the kidney, which monitors and regulates the body’s potassium levels. When kidney function is stalled, potassium builds in the bloodstream.

When blood contains too much potassium, it can cause the following problems:
  • Irregular heart beat
  • Cardiac arrest
  • Changes in muscle control
  • Paralysis
  • Muscle weakness and fatigue

Some drugs such as ibuprofen, certain high blood pressure medicines and certain diuretics can also increase potassium levels in the blood so should be used cautiously with Yaz to reduce the risk of hyperkalemia. Women should not take the drug if they have kidney failure, one kidney, liver disease, adrenal disease or a history of blood clots.

Gallbladder Disease

Yaz may increase the chances of gallbladder disease and surgical removal of the gallbladder called cholecystectomy. A study published in the Canadian Medical Association Journal concluded that drospirenone increased a woman’s risk for developing gallbladder problems by 20 percent compared to other birth control hormones. The study called it a “small, statistically significant increase in the risk of gallbladder disease,” but noted that it was not clear if those differences were clinically important.

Infographic stat about how drospirenone is linked to gallbladder disease.
Source: Canadian Medical Association Journal

Some studies say drospirenone is linked to gallbladder disease because of its diuretic effect. Other studies say the link between the drug and gallbladder disease is because the drug increases cholesterol levels, thus creating calcified bits of cholesterol in the gallbladder known as gallstones. Still, others say it is because drospirenone decreases the gallbladder’s movement and impedes bile flow.

Bayer says the research pointing to gallbladder problems is not clinically significant.

Other Potential Risks: Cancer, Liver Disease & High Blood Pressure

Past studies have suggested birth control pills like Yaz may increase the risk of breast cancer, according to the drug’s label. However, the label explains more recent studies have not confirmed the findings.

Still, the label warns women with a history of breast cancer or other estrogen- or progestin-sensitive cancer not to take the drug. It also notes that some studies have suggested the drugs are associated with an increased risk of cervical cancer, though other factors such as sexual behavior may have played a role.

Though extremely rare, this type of birth control can cause benign liver tumors which can rupture and cause death. Studies have also shown an increased risk of developing liver cancer in women who used the drugs for more than eight years, according to the drug’s label.

Women, especially older women who use the drug for an extended period of time, may be at risk for an increase in blood pressure and should watch for signs of the side effect. Women should not use the drug if they have high blood pressure.

Yaz Side Effects
  1. Black Box Warning Women over the age of 35 who smoke should not use Yaz because cigarette smoking increases the risk of serious side effects such as death from heart attack, blood clots or stroke.
  2. Most Common Side Effects in Clinical Trial The most frequently reported adverse reactions in women taking Yaz for contraception, acne or PMDD included headache, menstrual irregularities, nausea, breast tenderness and mood changes. Women who took the drug for PMDD also reported fatigue, decreased libido and increased weight.

Please seek the advice of a medical professional before making health care decisions.

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Kristin Compton
Written By Kristin Compton Writer

Kristin Compton's background is in legal studies. She worked as a paralegal before joining Drugwatch as a writer and researcher. She was also a member of the National Association of Legal Assistants. A mother and longtime patient, she has firsthand experience of the harmful effects prescription drugs can have on women and their children. Some of her qualifications include:

  • Bachelor of Arts in Legal Studies | Pre-Law from University of West Florida
  • Past employment with The Health Law Firm and Kerrigan, Estess, Rankin, McLeod & Thompson LLC
  • Personal experience battling severe food allergies, asthma and high-risk pregnancies
Edited By
Emily Miller
Emily Miller Managing Editor
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38 Cited Research Articles writers follow rigorous sourcing guidelines and cite only trustworthy sources of information, including peer-reviewed journals, court records, academic organizations, highly regarded nonprofit organizations, government reports and interviews with qualified experts. Review our editorial policy to learn more about our process for producing accurate, current and balanced content.

  1. ABC News. (2009, October 19). Bay Area Woman Sues Yaz Birth Control. Retrieved from
  2. American Heart Association. (n.d.). Heart Attack and Stroke Symptoms. Retrieved from
  3. American Heart Association. (2016, October 31). Hyperkalemia (High Potassium) Retrieved from
  4. American Society of Hematology. (2017). Blood Clots. Retrieved from
  5. Bird, S. et al. (2011, November). The Association Between Drospirenone and Hyperkalemia [Abstract]. Retrieved from
  6. Cornforth, T. (2017 February 2). Symptoms of Gallbladder Disease and Gallstones: Gallbladder Disease is More Likely to Affect Women. Retrieved from
  7. Cuomo, C., (2011, October 14). New Studies Find Yaz More Risky Than Other Leading Birth Control Pills: ABC News Investigates. ABC News. Retrieved from
  8. Digestive Disorders Health Center. (2010). Retrieved from
  9. Etminan, M. et al. (2011). Oral contraceptives and the risk of gallbladder disease: a comparative safety study. CMAJ. 183. 899 – 904. Retrieved from
  10. FDA. (2011, September 26). FDA Drug Safety Communication: Safety review update on the possible increased risk of blood clots with birth control pills containing drospirenone. Retrieved from
  11. FDA. (n.d.). Yaz package insert. Retrieved from
  12. Feeley, Jef et al. (2012, April 26). Bayer Yasmin Lawsuit Settlements Climb to $142 Million. “Bloomberg.” Retrieved from
  13. Fisk, M.C. & Feeley, J. (2011, December 6). Bayer Withheld Yasmin Data From U.S., Former Agency Chief Says. Bloomberg. Retrieved from
  14. Fletcher, J. (2018 , November 16). What are the most common gallbladder problems? Retrieved from
  15. Hallam, K. (2011, April 21). Birth-Control Pills with Drospirenone Raise Clot Risk in Study. Bloomberg. Retrieved from
  16. Lidegaard, O. et al. (2011, October) Risk of venous thromboembolism from use of oral contraceptives containing different progesterones and estrogen doses: Danish cohort study. Retrieved from
  17. MedlinePlus, NIH. (2015). Heart attack. Retrieved from
  18. MedlinePlus, NIH. (2015). High potassium level. Retrieved from
  19. MedlinePlus, NIH. (2015). Ischemic Stroke. Retrieved from
  20. MedlinePlus, NIH. (2015). Pulmonary embolus. Retrieved from
  21. MedlinePlus, NIH. (2015). Stroke. Retrieved from
  22. MedlinePlus, NIH. (2016). Blood Clots. Retrieved from
  23. MedlinePlus, NIH. (2016). Blood clots. Retrieved from
  24. MedlinePlus, NIH. (2016). Deep Vein Thrombosis. Retrieved from
  25. MedlinePlus, NIH. (2016). Deep vein thrombosis. Retrieved from
  26. MedlinePlus, NIH. (2016). Gallbladder Diseases. Retrieved from
  27. MedlinePlus, NIH. (2016). Thrombophlebitis. Retrieved from
  28. Mitchell, S. (2011, April 26). Yaz, Yasmin may pose higher risk of blood clots. Consumer Reports. Retrieved from
  29. NIH. (2011). What Are the Signs and Symptoms of Pulmonary Embolism? Retrieved from
  30. NIH. (2011). Venous Thromboembolism. Retrieved from
  31. NIH. (2017). What Are the Signs and Symptoms of a Stroke? Retrieved from,-Symptoms,-and-Complications
  32. Parkin, L. et al. (2011, April 21). Risk of venous thromboembolism in users of oral contraceptives containing drospirenone or levonorgestrel: nested case-control study based on UK General Practice Research Database. BMJ. Retrieved from
  33. Pulmonary embolism. (2011, September 27). Retrieved on March 20, 2012 from
  34. Singer, N. (2009, September 25). Health Concerns Over Popular Contraceptives. Retrieved from
  35. Stoppler, M. Hyperkalemia (High Blood Potassium). Retrieved from
  36. Vinogradova, Y. et al. (2015, May 26). Use of combined oral contraceptives and risk of venous thromboembolism: nested case-control studies using the QResearch and CPRD databases. Retrieved from
  37. Whitlock, RN, MSN, FNP-C, J. (2016 May 5). Signs and Symptoms of a Blood Clot: Do You Have a Blood Clot? Retrieved from
  38. Wilson, D. (2011, October 26). Study: Yaz Has Higher Risk of Blood Clots. New York Times. Retrieved from
View All Sources
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