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Norethisterone (oral contraceptive pill)

Written by Stephanie Nera, RPh, PharmD · Pharmacology

Updated Jul 01, 2021

Norethisterone is a hormonal drug used to prevent pregnancy. It is a progestin-only form of birth control pill, also called the “mini’-pill. It prevents pregnancy by making vaginal fluid thicker to make it harder for sperm to fertilize an egg in the womb. In addition, it temporarily prevents the release of an egg (ovulation) from the ovaries.


Know the basics

What is norethisterone used for?

  • Preventing pregnancy
  • Treat premenstrual syndrome (PMS)
  • Manage polycystic ovarian syndrome (PCOS)
  • Regulate menstruation
  • Postponing or delaying menstruation
  • Reducing the risk of certain cancers
  • Hormonal replacement therapy in postmenopausal women

How should I take norethisterone?

Read the directions on the packaging for complete information. Check the label and expiration date.

For oral dosage forms, swallow it whole without chewing, crushing, or dissolving it in liquid. Take it with or without food.

For parenteral dosage forms, only a licensed healthcare professional should administer it.

How do I store norethisterone?

Store this product at room temperature away from direct light and moisture. To prevent drug damage, you should not store it in the bathroom or the freezer. 

There may be different brands of this drug that may have different storage needs. So, it is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush this product down the toilet or pour them into a drain unless instructed to do so. Additionally, it is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Know the precautions & warnings

What should I know before using norethisterone?

Before using this drug, tell your doctor if you are/have:

  • Pregnant or breastfeeding.
  • An active smoker.
  • Taking any other medicines. This includes any prescription, OTC, and herbal remedies.
  • An allergy to any of the ingredients of this product.
  • Any other illnesses, disorders, or medical conditions.

Is it safe to take norethisterone during pregnancy or breastfeeding?

There strong evidence that this medication causes genital abnormalities in babies during pregnancy. Progestins are contraindicated (not allowed) during pregnancy. If you get pregnant while taking this drug, stop taking it immediately and consult your doctor. 

If you plan to breastfeed, wait until 6 weeks after delivery to start taking this drug.

This medication is pregnancy risk category X according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A= No risk
  • B= No risk in some studies
  • C= There may be some risk
  • D= Positive evidence of risk
  • X= Contraindicated
  • N= Unknown
  • Know the side effects

    What are the side effects of norethisterone?

    Like all drugs, this product may have side effects. If they occur, side effects are generally mild and resolve once treatment is finished or the dose is lowered. Some reported side effects include:

    • Irregular menstrual bleeding, spotting
    • Amenorrhea
    • Breast cancer
    • Visual disturbances
    • Migraine
    • Depression
    • Decreased glucose tolerance
    • Deep vein thrombosis (DVT)
    • Nausea, vomiting
    • Abdominal pain
    • Fatigue
    • Jaundice
    • Weight gain
    • Abnormal liver enzyme levels
    • Headache
    • Dizziness
    • Insomnia
    • Breast tenderness
    • Breast enlargement
    • Decreased libido
    • Change in cervical secretions
    • Cervical erosion
    • Acne
    • Melasma
    • Pruritus
    • Mood changes

    However, not everyone experiences these side effects. In addition, some people may experience other side effects. So, if you have any concerns about a side effect, please consult your doctor or pharmacist.

    Know the interactions

    What drugs may interact with norethisterone?

    This medication may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. 

    To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. 

    Drugs with known interactions:

    • Barbiturates
    • Phenytoin
    • Carbamazepine
    • Griseofulvin
    • Felbamate
    • Azole antifungals
    • Macrolide antibiotics
    • Verapamil, diltiazem
    • Ulipristal
    • St. Johns wort

    If you experience an adverse drug interaction, inform your doctor immediately to reevaluate your treatment plan. Approaches include dose adjustment, drug substitution, or ending therapy.

    Does food or alcohol interact with norethisterone?

    This drug may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Avoid consuming grapefruit products and alcohol. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

    What health conditions may interact with norethisterone?

    This drug may interact with underlying conditions. This interaction may worsen your health condition or alter the way the drug works. Therefore, it is important to always let your doctor and pharmacist know all the health conditions you currently have, especially:

    • Seizures
    • Migraines
    • Cardiovascular disease
    • Kidney disease
    • Depression
    • Hypertension
    • Diabetes
    • Dyslipidemia
    • Blood coagulation disorders

    Understand the dosage

    The information provided is not a substitute for any medical advice. Therefore, you should always consult with your doctor or pharmacist before using any medication.

    What is the dose for an adult?


    Via IM injection, administer 200 mg within the first 5 days of the menstrual cycle or immediately after birth. Repeat the dose every 8 weeks if needed.

    For oral dosage dorms, take 0.35 mg once a day. Start on the first day of menstruation or 21 days after delivery. Continue to take it until you intend to get pregnant.

    Delaying menstruation

    Take 5 mg three times a day for up to 14 days, starting 3 days before you normally expect to start menstruation.

    Dysfunctional uterine bleeding

    Take 5 mg three times a day for 10 days. To prevent recurrence, take 5 mg two times a day from the 19th to 26th days of the next two cycles. (2.5 to 10 mg per day for 5 to 10 days, if taking norethisterone acetate).

    Heavy menstruation

    Take 5 mg two to three times a day from the 19th to 26th day of your menstrual cycle. (The first day of bleeding is day 1).


    Take 5 mg three times a day for 20 days, starting on the 5th day of the cycle. Continue treatment for 3 to 4 cycles.


    Take 10 to 20 mg once a day, starting between the 1st and 5th days of the cycle, continuing for 4 to 6 months or longer. As norethisterone acetate, take 5 to 15 mg a day. Start at 5 mg daily and increase by 2.5 mg at 14-day intervals; take continuously for 6 to 9 months.

    Premenstrual syndrome (PMS)

    Take 5 mg 2 to 3 times a day on days 19 to 26 of your cycle. Repeat for several cycles, if needed.

    What is the dose for a child?

    There is no established pediatric dose. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

    How is medication available?

    Norethisterone is available in the following dosage forms and strengths:

    • Tablet: 0.35 mg
    • Tablet (containing norethisterone acetate): 5 mg

    What should I do in case of an emergency or overdose?

    In case of an emergency or an overdose, call your local emergency services or go to the nearest emergency room.

    What should I do if I miss a dose?

    If you miss a dose of norethisterone, take it as soon as possible. Within 3 hours after missing the dose, take it immediately and take the next dose at the regularly scheduled time. You will still be protected against pregnancy. 

    If you missed your dose for more than 3 hours, take it as soon as you remember. Take the next dose at the regularly scheduled time, even if that means taking 2 pills within a 24-hour period. Continue taking the pill as scheduled each day while using other forms of contraception (e.g. condoms, abstinence) for at least 48 hours to prevent pregnancy.

    Taking two doses close together or at the same time may increase the severity of side effects such as nausea, spotting, and moodiness. You may feel side effects such as nausea and mood swings.


    Hello Health Group does not provide medical advice, diagnosis or treatment.

    Written by

    Stephanie Nera, RPh, PharmD


    Updated Jul 01, 2021

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