Ethinyl Estradiol/Levonorgestrel Side Effects: What to Expect and When to Call Your Doctor

Ethinyl estradiol/levonorgestrel (EE/LNG) — the combination birth control pill sold as Aviane, Levora, Kurvelo, Seasonique, and many other brands — is generally safe and well-tolerated. But like any medication, it comes with a list of possible side effects ranging from minor and temporary to serious and requiring immediate medical attention. This guide gives you a clear, honest breakdown of what to expect.

The Boxed Warning: Cigarette Smoking and Cardiovascular Risk

The FDA requires a boxed warning — the most serious type — on all EE/LNG products.

Cigarette smoking increases the risk of serious cardiovascular events (blood clots, stroke, heart attack) from combination oral contraceptive use. This risk increases with age and the number of cigarettes smoked. EE/LNG is contraindicated in women who are over 35 years of age and smoke. If you smoke, talk to your doctor before starting or continuing this medication.

Common Side Effects (Usually Temporary)

The following side effects are commonly reported with EE/LNG. Many resolve after 2-3 months as your body adjusts to the hormone levels:

Headaches: One of the most frequently reported side effects. Usually mild; tell your doctor if headaches are severe, sudden, or different from your usual pattern.

Nausea and vomiting: More common in the first 1-3 months. Taking the pill with food or at bedtime can reduce nausea significantly.

Irregular or breakthrough bleeding: Spotting between periods is common, especially in the first few cycles. This typically resolves. Extended-cycle pills (91-day packs) are associated with more frequent breakthrough bleeding during the first few cycles.

Breast tenderness or pain: Often improves after the first 1-2 cycles.

Mood changes: Some patients report mood changes, including anxiety or depression. Tell your doctor if mood changes are significant or persistent.

Acne: Some patients experience acne improvement; others notice worsening, particularly in the first cycle.

Weight changes: Weight changes are reported but the link is not definitive. Most weight changes, if they occur, are attributed to water retention rather than fat gain.

Decreased libido: Some patients report changes in sexual desire. If this is bothersome, discuss with your provider.

Serious Side Effects — Call Your Doctor or Seek Emergency Care

The following symptoms may indicate a serious complication and require prompt medical evaluation. Some are medical emergencies. Do not wait to see if these resolve on their own:

Sudden severe headache, visual changes, or slurred speech: May indicate stroke — call 911.

Chest pain, pressure, or shortness of breath: May indicate heart attack or pulmonary embolism (blood clot in the lungs) — call 911.

Leg pain, swelling, redness, or warmth in the calf: May indicate deep vein thrombosis (blood clot in the leg) — seek emergency care.

Severe abdominal pain: May indicate liver tumor or gallbladder disease — contact your doctor.

Yellowing of skin or eyes (jaundice): May indicate liver problems — contact your doctor promptly.

Severe or persistent high blood pressure: EE/LNG can raise blood pressure. Your prescriber should monitor BP, and the medication may need to be discontinued if BP rises significantly.

Blood Clot Risk: Understanding the Numbers

All combination oral contraceptives increase the risk of venous thromboembolism (VTE — blood clots). This risk is real but should be put in context:

Non-pill users: ~2 per 10,000 women per year develop VTE

Combination pill users: ~3-9 per 10,000 women per year

Pregnant women: ~5-20 per 10,000 — higher than pill users

The risk is highest in the first year of use or when restarting after a gap of 4+ weeks. It is also higher in women with additional risk factors: obesity, smoking, immobility, and hereditary clotting disorders.

When Do Side Effects Typically Resolve?

Most common side effects — nausea, spotting, breast tenderness, and headaches — typically improve after 2-3 cycles as your body adjusts. If side effects are still bothersome after 3 months, talk to your prescriber about adjusting your formulation. Different hormone doses and progestin types can have meaningfully different side effect profiles.

Related Guides

For information on medications that interact with EE/LNG, see our guide on ethinyl estradiol/levonorgestrel drug interactions. To learn more about how the medication works and what conditions it treats, read what is ethinyl estradiol/levonorgestrel.