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Demulen 1/50 (Oral)

Generic name: ethinyl estradiol and ethynodiol diacetate

Brand names: Demulen 1/35, Demulen 1/50, Kelnor 1/35, Kelnor 1/35-28, Zovia 1/35e, Zovia 1/50e

Last updated April 22, 2026 0 views
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Uses for Demulen 1/50

Ethinyl estradiol and ethynodiol diacetate combination is used to prevent pregnancy. It is a birth control pill that has two types of hormones, ethinyl estradiol and ethynodiol diacetate, and when taken correctly, it prevents pregnancy. It works by stopping a woman's egg from fully developing each month. The egg can no longer accept sperm, which prevents fertilization (pregnancy).

No contraceptive method is 100 percent effective. Birth control methods like surgery to become sterile or abstaining from sex are more effective than birth control pills. Talk to your doctor about your options for birth control.

This medicine does not prevent HIV infection or other sexually transmitted diseases. It will not work as emergency contraception, such as after unprotected sexual contact.

This medicine is available only with your doctor's prescription.

This section was rewritten for readability and reviewed for meaning.

Precautions while using Demulen 1/50

It is very important for your doctor to check your progress at regular visits to ensure this medicine is working properly and does not cause unwanted effects. Your doctor may also want to check your blood pressure while you are taking this medicine.

Even though you are using this medicine to prevent pregnancy, you should know that using it while you are pregnant could harm your unborn baby. If you think you might be pregnant while using the medicine, tell your doctor right away. Make sure your doctor knows if you gave birth within 4 weeks before starting this medicine.

If you think you may be pregnant, stop using this medicine and check with your doctor immediately. You may have a higher risk of an ectopic pregnancy if you get pregnant while using this medicine. An ectopic pregnancy can be serious and life-threatening. It can also cause issues that may make it harder for you to become pregnant in the future.

Do not use this medicine with medicines that treat hepatitis C virus infection, including ombitasvir/paritaprevir/ritonavir, with or without dasabuvir (Technivie®, Viekira Pak®).

This medicine will not protect you from getting HIV/AIDS, herpes, or other sexually transmitted diseases. Tell your doctor if you or your partner starts having sexual intercourse with other people, or if you or your partner tests positive for a sexually transmitted disease. If this is a concern for you, talk with your doctor.

You might experience some light bleeding or spotting when you first start using this medicine. This is usually normal and should not last long. However, if you have heavy bleeding or if the bleeding lasts more than a few days in a row, call your doctor.

Do not use this medicine if you smoke cigarettes or if you are over 35 years old. Smoking while using ethinyl estradiol and norgestrel combination increases your risk of having a blood clot, heart attack, or stroke. Your risk is even higher if you are over age 35, if you have diabetes, high blood pressure, high cholesterol, or if you are overweight. Talk with your doctor about ways to stop smoking. Keep your diabetes under control. Ask your doctor about diet and exercise to manage your weight and blood cholesterol level.

Using this medicine may increase your risk of having blood clotting problems. Check with your doctor right away if you have pain in the chest, groin, or legs, especially the calves, difficulty breathing, a sudden, severe headache, slurred speech, sudden, unexplained shortness of breath, sudden loss of coordination, or changes in vision while using this medicine.

Using this medicine may increase your risk of having cancer of the breast or reproductive organs (e.g., endometrium, ovaries, cervix). Discuss this risk with your doctor. Check with your doctor right away if you experience abnormal vaginal bleeding.

Check with your doctor immediately if you have pain or tenderness in the stomach, dark urine, pale stools, loss of appetite, nausea, vomiting, or yellowing of the eyes or skin. These could be signs of a serious liver problem.

Check with your doctor right away if you experience blurred vision, difficulty reading, or any other changes in vision during or after treatment. Your doctor may want an eye doctor (ophthalmologist) to examine your eyes.

This medicine may increase your risk of gallbladder disease. Check with your doctor if you start having stomach pains, nausea, and vomiting.

Make sure any doctor or dentist who treats you knows that you are using this medicine. The results of some medical tests may be affected by this medicine.

Do not take other medicines unless you have discussed them with your doctor. This includes prescription and nonprescription (over-the-counter [OTC]) medicines as well as herbal or vitamin supplements.

This section was rewritten for readability and reviewed for meaning.

Before using Demulen 1/50

In deciding to use a medicine, you and your doctor need to weigh the risks against the benefits. Here are some important considerations for this medicine:

Allergies

Inform your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also, let your health care professional know if you have any other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, be sure to read the label or package ingredients carefully.

Pediatric

There have not been appropriate studies on how ethinyl estradiol and ethynodiol diacetate combination affects children. However, there are no known pediatric-specific problems that would limit the use of this medicine in teenagers. This medicine can be used for birth control in teenage females but should not be used before menstruation starts.

Geriatric

There is no available information on how ethinyl estradiol and ethynodiol diacetate combination affects older adults.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be used together at all, while others may be used together with caution. In these cases, your doctor may need to adjust the dose or take other precautions. It is especially important that your healthcare professional knows if you are taking any of the following medicines. The following interactions are based on their potential significance but are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to prescribe this medication or change some of the other medicines you take.

  • Dasabuvir
  • Ombitasvir
  • Paritaprevir
  • Ritonavir
  • Tranexamic Acid

Using this medicine with any of the following medicines is usually not recommended but may be necessary in some cases. If both medicines are prescribed, your doctor may adjust the dose or frequency of use for one or both medicines.

  • Amifampridine
  • Amobarbital
  • Amoxicillin
  • Ampicillin
  • Amprenavir
  • Anagrelide
  • Apalutamide
  • Aprepitant
  • Armodafinil
  • Artemether
  • Bacampicillin
  • Belzutifan
  • Betamethasone
  • Bexarotene
  • Boceprevir
  • Bosentan
  • Bupropion
  • Butabarbital
  • Butalbital
  • Carbamazepine
  • Carbenicillin
  • Cefaclor
  • Cefadroxil
  • Cefdinir
  • Cefditoren
  • Cefixime
  • Cefpodoxime
  • Cefprozil
  • Ceftazidime
  • Ceftibuten
  • Cefuroxime
  • Cenobamate
  • Ceritinib
  • Clobazam
  • Cloxacillin
  • Cobicistat
  • Colesevelam
  • Cyclacillin
  • Cyclosporine
  • Dabrafenib
  • Darunavir
  • Dexamethasone
  • Dicloxacillin
  • Dipyrone
  • Donepezil
  • Doxycycline
  • Efavirenz
  • Elagolix
  • Elvitegravir
  • Encorafenib
  • Enzalutamide
  • Eslicarbazepine Acetate
  • Etravirine
  • Felbamate
  • Fosamprenavir
  • Fosaprepitant
  • Fosphenytoin
  • Fostemsavir
  • Glecaprevir
  • Grazoprevir
  • Griseofulvin
  • Guar Gum
  • Indinavir
  • Iron
  • Isotretinoin
  • Ivosidenib
  • Lesinurad
  • Lixisenatide
  • Lopinavir
  • Lorlatinib
  • Lumacaftor
  • Mavacamten
  • Mephobarbital
  • Meropenem
  • Methohexital
  • Minocycline
  • Mitapivat
  • Mitotane
  • Mobocertinib
  • Modafinil
  • Mycophenolate Mofetil
  • Mycophenolic Acid
  • Nafcillin
  • Nelfinavir
  • Nevirapine
  • Nirmatrelvir
  • Octreotide
  • Oxacillin
  • Oxcarbazepine
  • Oxytetracycline
  • Paclitaxel
  • Paclitaxel Protein-Bound
  • Penicillin G
  • Penicillin G Procaine
  • Penicillin V
  • Pentobarbital
  • Phenobarbital
  • Phenylbutazone
  • Phenytoin
  • Pibrentasvir
  • Piperaquine
  • Pitolisant
  • Prednisolone
  • Prednisone
  • Primidone
  • Red Clover
  • Rifabutin
  • Rifampin
  • Rifapentine
  • Rilpivirine
  • Ritonavir
  • Rufinamide
  • Saquinavir
  • Secobarbital
  • Simeprevir
  • Somatrogon-ghla
  • St John's Wort
  • Sugammadex
  • Sultamicillin
  • Tazemetostat
  • Telaprevir
  • Telotristat Ethyl
  • Tetracycline
  • Theophylline
  • Thiopental
  • Thioridazine
  • Ticarcillin
  • Tigecycline
  • Tirzepatide
  • Tizanidine
  • Topiramate
  • Troglitazone
  • Ulipristal
  • Valproic Acid
  • Voxilaprevir

Using this medicine with any of the following medicines may increase the risk of certain side effects, but it may be necessary to use both. If both are prescribed, your doctor may adjust the dose or frequency of use for one or both medicines.

  • Amitriptyline
  • Atazanavir
  • Atorvastatin
  • Clomipramine
  • Diazepam
  • Doxepin
  • Etoricoxib
  • Ginseng
  • Imipramine
  • Lamotrigine
  • Levothyroxine
  • Licorice
  • Liothyronine
  • Lorazepam
  • Parecoxib
  • Roflumilast
  • Selegiline
  • Temazepam
  • Tipranavir
  • Triazolam
  • Troleandomycin
  • Valdecoxib
  • Voriconazole
  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be taken around the time of eating food or certain types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also cause interactions. The following interactions are based on their potential significance but are not necessarily all-inclusive.

Using this medicine with any of the following may increase the risk of certain side effects, but it may be unavoidable in some cases. If used together, your doctor may adjust the dose or provide special instructions about the use of food, alcohol, or tobacco.

  • Caffeine

Other Medical Problems

Having other medical issues may affect the use of this medicine. Make sure to inform your doctor if you have any other medical problems, especially:

  • Abnormal or unusual vaginal bleeding or
  • Blood clots (e.g., deep vein thrombosis, pulmonary embolism), or history of or
  • Breast cancer, known or suspected, or history of or
  • Cervical cancer, known or suspected, or history of or
  • Endometrial cancer, known or suspected, or history of or
  • Heart attack, history of or
  • Heart or blood vessel disease (e.g., coronary artery disease), or history of or
  • Jaundice during pregnancy or from past hormonal therapy or
  • Liver disease, including tumors or cancer or
  • Ovarian cancer, known or suspected, or history of or
  • Stroke, history of or
  • Tumors (estrogen-dependent), known or suspected—This medicine should not be used in patients with these conditions.
  • Depression, history of or
  • Diabetes or
  • Gallbladder disease, history of or
  • Hyperlipidemia (high cholesterol or fats in the blood) or
  • Kidney disease or
  • Migraine headache or
  • Seizures, history of or
  • Tuberculosis (TB) infection—This medicine may worsen these conditions.
  • Diarrhea or
  • Vomiting—These may reduce the absorption of ethinyl estradiol and ethynodiol diacetate combination in the body.

This section was rewritten for readability and reviewed for meaning.

Side Effects of Demulen 1/50

Along with its needed effects, a medicine may cause some unwanted effects. Not all of these side effects may occur, but if they do, they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Incidence not known

  • Absent, missed, or irregular menstrual periods
  • anxiety
  • bloody stools
  • blurred vision
  • breast tenderness, enlargement, discharge
  • changes in skin color, pain, tenderness, or swelling of the foot or leg
  • chest pain or discomfort
  • chills
  • clay-colored stools
  • confusion
  • cough
  • dark or cloudy urine
  • decrease in urine output or decrease in urine-concentrating ability
  • diarrhea
  • difficulty in speaking
  • dizziness or lightheadedness
  • double vision
  • fainting
  • fast heartbeat
  • fever
  • headache, severe and throbbing
  • inability to move the arms, legs, or facial muscles
  • inability to speak
  • itching of the vagina or outside the genitals
  • loss of appetite
  • nausea
  • nervousness
  • pain during sexual intercourse
  • pain or discomfort in the arms, jaw, back or neck
  • pounding in the ears
  • slow or fast heartbeat
  • slow speech
  • stomach pain and tenderness
  • stopping of menstrual bleeding
  • sweating
  • swelling
  • swelling, pain, or tenderness in the upper abdominal area
  • tenderness, pain, swelling, warmth, skin discoloration, and prominent superficial veins over the affected area
  • thick, white curd-like vaginal discharge without odor or with mild odor
  • troubled breathing
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting
  • vomiting of blood
  • yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Your health care professional may also be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  • Acne
  • changes in appetite
  • changes in weight
  • decreased interest in sexual intercourse
  • decreased milk production
  • light vaginal bleeding between regular menstrual periods
  • loss in sexual ability, desire, drive, or performance
  • mental depression
  • patchy brown or dark brown discoloration of the skin

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

In the U.S.

  • Demulen 1/35
  • Demulen 1/50
  • Kelnor 1/35
  • Kelnor 1/35-28
  • Zovia 1/35e
  • Zovia 1/50e

Available Dosage Forms:

  • Tablet

Therapeutic Class: Contraceptive

Pharmacologic Class: Estrogen

This section was rewritten for readability and reviewed for meaning.

Proper use of Demulen 1/50

It is very important that you use this medicine exactly as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered.

To make using oral contraceptives as safe and reliable as possible, you should understand how and when to take them and what effects may be expected.

This medicine comes with patient instructions. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.

When you begin using this medicine, your body will require at least 7 days to adjust before a pregnancy will be prevented. Use a second form of contraception, such as a condom, spermicide, or diaphragm, for the first 7 days of your first cycle of pills.

Take this medicine at the same time each day. Birth control pills work best when no more than 24 hours pass between doses.

Do not skip or delay taking your pill by more than 24 hours. If you miss a dose, you could get pregnant. Ask your doctor for ways to help you remember to take your pills or about using another method of birth control.

You may feel sick or nauseated, especially during the first few months that you take this medicine. If your nausea is continuous and does not go away, call your doctor.

Use another form of birth control if you vomit or have diarrhea after taking the pills until you check with your doctor.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Your doctor may ask you to begin your dose on the first day of your menstrual period (called Day 1 start) or on the first Sunday after your menstrual period starts (called Sunday start). When you begin on a certain day it is important that you follow that schedule, even if you miss a dose. Do not change your schedule on your own. If the schedule that you use is not convenient, talk with your doctor about changing it. For a Sunday start, you need to use another form of birth control (eg, condom, diaphragm, spermicide) for the first 7 days.

You should begin your next and all subsequent 28-day regimens of therapy on the same day of the week as the first regimen began and follow the same schedule.

  • For oral dosage form (tablets):For contraception (to prevent pregnancy): Adults and teenagers—One light yellow tablet (active) taken at the same time each day for 21 consecutive days followed by one white (inert) tablet daily for 7 days per menstrual cycle. Children—Use and dose must be determined by your doctor.

Missed Dose

Call your doctor or pharmacist for instructions.

This medicine has specific patient instructions on what to do if you miss a dose. Read and follow these instructions carefully and call your doctor if you have any questions.

  • If you miss one active pill: Take it as soon as you can, then take your next pill at your regular schedule.
  • If you miss two active pills in week 1 or 2: Take two pills as soon as you can and two more pills the next day. Continue taking one pill a day until you finish the pack. Use a second form of birth control (eg, condom, spermicide) for 7 days after you miss a dose.
  • If you miss two active pills in week 3, or you miss three or more active pills in a row in weeks 1, 2, or 3: Day 1 start: Throw out the rest of the pack and start a new pack that same day. Use a second form of birth control (eg, condom, spermicide) for 7 days after you miss a dose. 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 (eg, 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 if you do not take a pill on time. The more pills you miss, the more likely you are to have bleeding.

Make sure your doctor knows if you miss your period 2 months in a row, because this could mean that you are pregnant.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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