Norethindrone belongs to the class of medications called oral contraceptives (birth control pills). It is a progestin birth control medication used for the prevention of pregnancy. Progestins can prevent fertilization by preventing a woman's egg from fully developing and by causing thickening of the cervical mucus. Progestin-only pills (without estrogen added) are often called the mini pill.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else. It can be harmful for people to take this medication if their doctor has not prescribed it.

Norethindrone is taken as one tablet daily, at the same time every day, with or without food. See the package insert for information on where in your cycle to start and what to do if you forget to take a pill.

Take one tablet daily for 28 days then start a new pack on the next day. Do not wait any days between packs. Your period should occur during the last 7 days of using the pill pack. Continue to take norethindrone every day, even if you are having some menstrual bleeding.

You may wish to use a second method of birth control (e.g., latex condoms and spermicidal foam or gel) for the first 7 days of the first cycle of pill use. This will provide a backup in case pills are forgotten while you are getting used to taking them.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. The effectiveness of this medication depends on taking the medication at the same time each day. If you forget to take a pill, refer to the package insert for information on how to proceed. If you miss pills at any time, or are late taking a pill by 3 hours or more, the risk of becoming pregnant increases. Refer to your package insert information for instruction on when you will need to use a second method of birth control. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from moisture and keep it out of the reach of children.

Each green, unscored tablet, debossed with "406" on one side and plain on the other side, contains 0.35 mg of norethindrone. Nonmedicinal ingredients: corn starch, D&C Yellow No. 10, ethyl cellulose, FD&C Blue No. 1, lactose anhydrous, magnesium stearate, microcrystalline cellulose, polyvinyl pyrrolidone, sodium starch glycolate, and talc.

Do not take this medication if you:

• are allergic to norethindrone or any ingredients of this medication
• are allergic to progestins
• are or may be pregnant
• have active liver disease
• have or have had benign or malignant liver tumours
• have or may have breast cancer
• have undiagnosed abnormal vaginal bleeding

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• acne
• breast pain or tenderness
• decreased amounts of menstrual bleeding at monthly periods
• dizziness
• fatigue
• loss or gain of body, facial, or scalp hair
• mild headache
• nausea
• skin rash
• vomiting
• weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• stopping of menstrual periods
• symptoms of ectopic pregnancy (e.g., sudden lower abdominal pain, back pain, or light menstrual bleeding)
• uterine bleeding between regular menstrual periods

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnancy or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Breast cancer: Some studies have suggested the possibility of a link between birth control pills and breast cancer, but nothing conclusive has been found involving this medication. Women with breast cancer should not use birth control pills, as the role of female sex hormones in breast cancer has not been fully determined.

Cervical cancer: Some studies have suggested the possibility of a link between birth control pills and cervical cancer, but nothing conclusive has been found involving this medication. Women with cervical cancer should not use birth control pills, as the role of female sex hormones in cervical cancer has not been fully determined.

Depression: Women with a history of depression may be more likely to have a recurrence while taking birth control pills. If you have a history of depression or other mental health conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Diabetes: Norethindrone may cause slight increases in blood sugar levels (may cause a loss of blood glucose control) and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication.

If you have diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Irregular menstruation: Irregular menstrual patterns are common among women using progestin-only birth control pills. If you notice changes in your usual menstrual patterns, check with your doctor. If you go a prolonged time without bleeding, you should have a pregnancy test.

Laboratory tests: Progestin-only birth control pills may affect how some laboratory tests work. If you are having blood tests to check your thyroid or a Pap smear, let your doctor know that you are taking norethindrone.

Liver function: Some studies have suggested the possibility of a link between birth control pills and cancerous and non-cancerous liver tumours, but nothing conclusive has been found involving this medication.

This medication may cause changes in liver function. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Migraine and headache: If you currently suffer from severe headaches or migraines that become more frequent or increase in intensity, or if you develop migraines or headaches that become persistent and bothersome after starting norethindrone, contact your doctor.

Regular checkups: While you are taking this medication, have follow-up visits and a physical examination done every year by your doctor.

Return to fertility: Studies are limited, but they show a rapid return of normal ovulation and no delay to fertility after stopping this medication.

Sexually transmitted infections (STIs): Birth control pills do not protect against STIs, including HIV/AIDS. For protection against STIs, use latex condoms.

Smoking: Cigarette smoking increases the risk of serious problems with the heart and blood vessels. This risk increases with age and becomes significant after age 35. Do not smoke if you use this medication, especially if you are over 35.

Pregnancy: Birth control pills should not be taken by pregnant women. If you are taking birth control pills and discover that you are pregnant, stop the birth control pills and see your doctor. However, there is no conclusive evidence that the progestin contained in this medication will be harmful to the unborn child.

Breast-feeding: If the use of birth control pills is started after breast-feeding has begun, there does not appear to be any effect on the quantity and quality of the milk. There is no evidence that progestin-only birth control pills such as this medication are harmful to the nursing infant. No side effects have been found on breast-feeding performance or on the health, growth, or development of the infant.

There may be an interaction between norethindrone and any of the following:

• aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• barbiturates (e.g., butalbital, phenobarbital)
• bosentan
• bromocriptine
• chloral hydrate
• clarithromycin
• cobicistat
• colesevelam
• deferasirox
• dexamethasone
• diabetes medications (e.g., acarbose, canagliflozin, glyburide, insulin, linagliptin, lixisenatide, metformin, rosiglitazone)
• elagolix
• flibanserin
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• lamotrigine
• mifepristone
• mitotane
• modafinil
• mycophenolate
• octreotide
• certain protein kinase inhibitors (e.g., ceritinib, dabrafenib, erlotinib, idelalasib, vemurafenib)
• retinoic acid medications (e.g., acitretin, etretinate, isotretinoin, tretinoin)
• rifabutin
• rifampin
• rufinamide
• St. John's wort
• sarilumab
• seizure medications (e.g., carbamazepine, clobazam, eslicarbazepine, ethosuximide, felbamate, oxcarbazepine, phenytoin, topiramate)
• thalidomide
• tocilizumab
• tranexamic acid
• tretinoin
• ulipristal
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications,
• or leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.