Yaz 28 Side Effects: What to Expect and When to Call Your Doctor

Like all hormonal contraceptives, Yaz 28 comes with a range of possible side effects — from mild and temporary to rare but serious. Most people tolerate it well, but knowing what to expect and when to seek medical attention can make a big difference in your experience. Here's a complete guide.

Common Side Effects (Usually Mild and Often Improve Over Time)

These side effects were reported in clinical trials for Yaz 28 and are generally mild. Many improve after the first 1–3 months as your body adjusts to the hormones:

Irregular bleeding or spotting — 8 to 25% of women experienced unscheduled bleeding per 28-day cycle in clinical trials. Most common in the first 3 months. Usually resolves on its own.

Nausea — one of the most commonly reported side effects. Taking Yaz 28 after the evening meal or at bedtime (as the FDA label recommends) can help reduce nausea.

Headaches — mild headaches are common when starting a new pill. Note: severe or unusual headaches can be a warning sign (see below).

Breast tenderness — breast pain or sensitivity, especially in the first few weeks. Usually mild.

Mood changes — mood swings, irritability, or depressed mood. Reported in 2.3% of clinical trial participants. Talk to your prescriber if mood changes are significant or persistent.

Decreased sex drive — some women experience reduced libido on hormonal birth control.

Vaginal discharge or yeast infections — changes in vaginal discharge or increased susceptibility to yeast infections may occur.

Absence of withdrawal bleeding — 6 to 10% of women experienced cycles with no withdrawal bleeding during contraception trials. If you miss a period, take a pregnancy test to rule out pregnancy.

Serious Side Effects — Seek Medical Attention Immediately

These side effects are rare but serious. Know the warning signs:

Blood clots (venous thromboembolism — VTE): Yaz 28 contains drospirenone, which some studies suggest may carry a higher VTE risk than levonorgestrel-containing pills. Signs: leg swelling, redness, or pain (DVT); sudden shortness of breath or chest pain (PE). Risk is highest in the first 6 months of use.

Stroke: Signs include sudden severe headache, numbness or weakness on one side of the body, trouble speaking or understanding speech, sudden vision changes, loss of balance. Call 911 immediately.

Heart attack: Signs include chest pain or pressure, sweating, nausea, dizziness, or shortness of breath. Call 911 immediately.

High blood pressure: Yaz 28 may elevate blood pressure or worsen existing hypertension. If your systolic pressure reaches 180 or your diastolic reaches 120, get medical attention immediately.

Liver problems: Signs include yellowing of skin or eyes (jaundice), dark urine, severe upper abdominal pain, or unusual fatigue. Stop Yaz and contact your doctor immediately.

High potassium (hyperkalemia): Drospirenone can increase potassium levels. Symptoms: muscle weakness, fatigue, irregular heartbeat. More concerning in patients on ACE inhibitors, ARBs, or other potassium-raising medications.

The Boxed Warning: Smoking and Cardiovascular Risk

Yaz 28 carries an FDA boxed warning — the highest level of safety warning — related to cigarette smoking. Smoking while taking Yaz 28 (or any estrogen-containing birth control) significantly increases the risk of serious cardiovascular events including stroke and heart attack. This risk increases with age and the number of cigarettes smoked per day. Women over 35 who smoke should not take Yaz 28 or any combined oral contraceptive.

Side Effects Specific to Yaz 28 vs. Other Birth Control Pills

Yaz 28's progestin, drospirenone, is a spironolactone analogue with anti-androgenic and anti-mineralocorticoid properties. This means:

It may cause less bloating than progestins with more androgenic activity (due to its anti-mineralocorticoid effect)

It may cause less weight gain compared to some other progestins

It has a higher VTE risk than levonorgestrel-based pills — possibly up to 3 times higher according to some population studies

It can raise potassium levels — relevant if you take other medications that also raise potassium

When to Call Your Doctor About Yaz 28 Side Effects

Call your prescriber (not just Google) if you experience:

Breakthrough bleeding that lasts more than 3 months or is heavy

Missed periods (to rule out pregnancy)

Significant mood changes or worsening depression

New or severe headaches

Vision changes or contact lens discomfort

Elevated blood pressure

For more on how Yaz 28 interacts with other medications, see our guide on Yaz 28 drug interactions.