Ethinyl estradiol/ethynodiol diacetate (By mouth)

Ethinyl Estradiol (ETH-i-nil es-tra-DYE-ol), Ethynodiol Diacetate (e-thye-noe-DYE-ol dye-AS-e-tate)

Prevents pregnancy.

Brand Name(s):

Kelnor 1/35, Kelnor 1/50, Zovia 1/35e, Zovia 1/50e

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. Do not use it if you had an allergic reaction to ethinyl estradiol or ethynodiol diacetate, or if you are pregnant. Tell your doctor if you have liver disease or liver cancer, breast cancer, ovarian cancer, cancer of the uterus, heart disease, a blood vessel disorder, or a history of blood clots, heart attacks, or strokes. Do not use this medicine if you have unusual vaginal bleeding, or if you have ever had jaundice (yellow eyes or skin) caused by pregnancy or birth control pills.

How to Use This Medicine:


  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • You may begin taking the pills on the first day of your menstrual period, or on the first Sunday after your period begins. If your period starts on a Sunday, start taking this medicine on that day. Then continue taking one pill each day in the order that they appear in the package.
  • You should also use a second form of birth control (including condoms, diaphragms, or contraceptive foams and jellies) when you first start using this medicine.
  • Take your pill at the same time every day. Birth control pills work best when there is no more than 24 hours between doses.
  • Missed dose:
    • If you miss one light yellow pill, take it as soon as you can, then take your next pill at your regular schedule.
    • If you miss two light yellow pills in week 1 or 2, take two pills as soon as you can and two more pills the next day. Then go back to your regular schedule of taking one pill every day. Use another kind of birth control until you have been taking light yellow pills for seven days in a row.
    • If you miss two light yellow pills in week 3 or three or more light yellow pills in a row in weeks 1, 2, or 3:
      • Day 1 start - Throw out the rest of your pills and start a new pack on the same day.
      • Sunday start - Continue taking one pill a day until Sunday, then throw out the rest of the pack and start a new pack that same day.
      • Use a second form of birth control (including condom, spermicide) for 7 days after you miss a dose, to prevent pregnancy.
    • If you miss any white pills, throw away the missed pills and go back to your regular schedule.
    • You could have light bleeding or spotting any time you do not take a pill on schedule. The more pills you miss, the more likely you are to have bleeding.
    • If you miss two periods in a row, call your doctor for a pregnancy test before you take any more pills.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use this medicine together with medicine to treat hepatitis C virus infection, including ombitasvir/paritaprevir/ritonavir, with or without dasabuvir.
  • Some medicines can affect how ethinyl estradiol/ethynodiol diacetate works. Tell your doctor if you are using any of the following:
    • Phenylbutazone, troglitazone
    • Medicine to treat infection (including ampicillin, griseofulvin, tetracyclines)
    • Medicine to teat seizures (including phenobarbital, phenytoin

Warnings While Using This Medicine:

  • It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
  • Tell your doctor if you are breastfeeding or if you have recently been pregnant. Tell your doctor if you have high blood pressure, high cholesterol in the blood, diabetes, breast lumps, migraine headaches, tuberculosis, or a history of depression, seizures, gallbladder disease, heart disease, kidney disease, or irregular monthly periods, or a family history of breast cancer.
  • This medicine may cause the following problems:
    • Increased risk of heart attack, stroke, or blood clots
    • Increased risk of cancer (including cancer of the breast, endometrium, ovaries, and cervix)
    • Liver problems
    • Eye or vision problems
    • Gallbladder disease
    • High cholesterol in the blood
    • High blood pressure
  • This medicine will not protect you from getting HIV/AIDS or other sexually transmitted diseases.
  • You might have some light bleeding or spotting when you first start using this medicine. However, if you have heavy bleeding or the bleeding lasts more than seven days in a row, call your doctor.
  • Tell any doctor or dentist who treats you that you are using this medicine. You may need to stop using this medicine several days before you have surgery or medical tests.
  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Breast lumps, tenderness, pain, swelling, or discharge
  • Chest pain or tightness, trouble breathing, or coughing up blood
  • Dark urine, pale stools, loss of appetite, yellow skin or eyes
  • Irregular, late, or missed menstrual periods
  • Numbness or weakness on one side of your body
  • Pain in your lower leg (calf)
  • Rapid weight gain, swelling in your hands, ankles, or feet
  • Sudden and severe stomach pain, nausea, vomiting, lightheadedness
  • Sudden severe headache, problems with vision, speech, or walking
  • Unusual or unexpected vaginal bleeding or heavy bleeding

If you notice these less serious side effects, talk with your doctor:

  • Acne, mild skin rash, or darkened skin on your face
  • Loss of hair
  • Mild nausea, vomiting, diarrhea, stomach cramps, bloated feeling
  • Mood changes, depression, nervousness, trouble sleeping
  • Problems with wearing contact lenses
  • Rapid weight gain or loss
  • Vaginal spotting or light bleeding, itching, discharge

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 11/6/2020

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