What is Ethynodiol Diaacetate used for?

Ethynodiol Diaacetate is used as an oral contraceptive to prevent pregnancy.

How should I take Kelnor 1/50 to prevent pregnancy?

You should take one tablet every 24 hours at the same time to ensure it is most effective.

Can I smoke while taking Ethynodiol Diaacetate?

Smoking increases the risk of serious heart and blood vessel problems while using this medication, especially if you are over 35 or smoke heavily.

What should I do if I miss a pill or start on a Sunday?

If using a Sunday start schedule, use a backup method of protection for the first week of the first cycle.

Is Ethynodiol Diaacetate safe to take if I am breastfeeding?

It may reduce your milk supply and pass into your milk; it is recommended to use other birth control until you have weaned.

Can Ethynodiol Diaacetate cause blood clots?

Yes, use of oral contraceptives is associated with an increased risk of serious conditions like blood clots (thrombosis) and stroke.

What happens if I take too much Ethynodiol Diaacetate?

An overdose may cause nausea and withdrawal bleeding.

Are there any common side effects of Kelnor 1/50?

Common side effects include nausea, spotting, or breakthrough bleeding.

Ethynodiol Diacetate | CAS 297-76-7 | ONKUMRGIYFNPJW

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Oral contraceptive (birth control pill)

How it worksThis medication works mainly by stopping ovulation (the release of an egg). It may also change cervical mucus to make it harder for sperm to reach the uterus and change the lining of the uterus to make implantation less likely.

Brand names:OVULEN-28, OVULEN

Used for

Prevention of pregnancy

Conditions

Pregnancy prevention

Class

ProgestinOral ContraceptiveOral contraceptive (birth control pill)Reproductive systemCardiovascular systemHepatic system

How to take

FormsTablet

RoutesOral

To get the best protection, take one tablet every 24 hours at the same time. For a 28-day pack, take 21 active pink tablets followed by 7 white placebo tablets.

If starting on a Sunday, use a backup method of protection for the first week. If starting on 'Day 1' (the first day of your period), follow the daily schedule as directed.

Missed dose: To achieve maximum effectiveness, tablets must be taken exactly as directed and at 24-hour intervals.

Key warnings

Smoking increases the risk of serious heart and blood vessel problems when using this medication. This risk is higher if you are older or smoke heavily (15 or more cigarettes a day). Women using this drug are strongly advised not to smoke.

·Smoking increases the risk of serious heart and blood vessel problems when using this medication. This risk is higher if you are older or smoke heavily (15 or more cigarettes a day). Women using this drug are strongly advised not to smoke.
·Smoking significantly increases cardiovascular risks.
·Increased risk of blood clots, stroke, and heart attack.
·Risk of liver tumors or gallbladder disease.
·Risk increases with other factors like obesity, diabetes, or high blood pressure.

Do not use if

·History of blood clots or vascular disease.
·History of heart attack or coronary artery disease.
·Current or past breast cancer or other hormone-sensitive cancers.
·Undiagnosed abnormal vaginal bleeding.
·History of liver tumors or jaundice related to pregnancy/pill use.
·Known or suspected pregnancy.

Side effects

Common

NauseaSpottingBreakthrough bleeding

Serious

·Blood clots (thrombosis or embolism)
·Heart attack
·Stroke
·Liver tumors or liver issues
·Gallbladder disease
·High blood pressure

Seek help if

·Signs of blood clots (thrombosis)
·Chest pain or heart attack symptoms
·Signs of stroke (cerebral hemorrhage)
·Severe abdominal pain (gallbladder or liver issues)

Interactions

·Rifampin may make the pill less effective and cause irregular bleeding.
·Certain medications like barbiturates, phenytoin, and some antibiotics may reduce effectiveness.
·Trogliptazone can lower hormone levels by about 30%, potentially leading to pregnancy.
·Do not take this with certain Hepatitis C drug combinations (containing ombitasvir/paritaprevir/ritonavir) due to risk of liver enzyme elevation.

Special populations

PregnancyThis medication is categorized as Pregnancy Category X and should not be used if you are pregnant or suspect you might be.

BreastfeedingSmall amounts of these hormones may pass into breast milk, which could cause issues like jaundice or breast enlargement in the baby. It may also decrease the amount and quality of your milk. It is advised to use other birth control methods until you have finished breastfeeding.

PediatricThis drug is intended for women of reproductive age. It is expected to be safe for adolescents aged 16 and older, but it should not be used before a girl has started her period.

Talk to your doctor

Monitor

·Blood pressure
·Signs of blood clots
·Liver function
·Unusual vaginal bleeding

Questions to ask

·Does my history of liver issues affect my ability to use this?
·How will my smoking habit impact the risks of this medication?
·Will my current medications interact with Ethynodiol Diaacetate?
·Is this safe for me if I am breastfeeding?

Practical

OverdoseIf a large amount is taken, you may experience nausea and withdrawal bleeding.

Ingredients

Allergens

Lactose

Inactive

Anhydrous lactoseMagnesium stearateMicrocrystalline cellulosePolacrilin potassiumPovidone K30D&C Red No. 30 Aluminum LakeD&C Yellow No. 10 Aluminum Lake

Educational summary derived from FDA labeling, AI-assisted. Not medical advice — consult a healthcare professional. Updated 2026-04-25.