Micronor contraceptive tablets are a type of hormonal contraceptive commonly known as the 'mini pill' or progestogen-only pill (POP). They contain the active ingredient norethisterone, which is a synthetic progestogen, similar to the natural progestogens produced by the body.
Micronor contraceptive tablets prevent pregnancy in three ways. Firstly, they affect the natural mucus at the neck of the womb (cervix). Norethisterone increases the thickness of this mucus, making it more difficult for sperm to cross from the vagina into the womb. By preventing sperm entering the womb, successful fertilisation of an egg, leading to pregnancy, is less likely.
Norethisterone also changes the quality of the womb lining (endometrium). The changes prevent any eggs that have been fertilised from successfully implanting onto the wall of the womb.
Lastly, norethisterone may prevent the release of an egg from the ovaries, however this may not occur in all women who take the mini-pill.
Micronor contraceptive tablets should be taken every day on a continuous basis, i.e. you take the packs back to back without a break, including when you are having a period. (This is unlike the combined pill, which is usually taken every day for three weeks, followed by a pill-free week.)
The tablets should be swallowed with a drink. They can be taken either with or without food.
Micronor contraceptive tablets must be taken continuously, at the same time every day, for them to be effective at preventing pregnancy.
If you are more than three hours late taking your pill, you will not be protected against pregnancy. If this happens, you should use an extra barrier method of contraception, e.g. condoms, for the next two days, while continuing with your normal pill taking.
Medicines and their possible side effects can affect individual people in different ways. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect. The following are some of the side effects that are known to be associated with norethisterone:
Common (affect between 1 and 10 out of every 100 women)
- Nausea and vomiting.
- Changes in menstrual bleeding, e.g. irregular bleeding or sometimes stopping of bleeding.
- Breast tenderness.
- Weight gain.
Uncommon (affect between 1 and 10 out of every 1000 women)
- Mood changes, including depression.
- Hair loss or increased hair growth.
- Vaginal discharge.
- Cysts on the ovaries.
- Painful periods.
- Fluid retention (oedema).
- Decreased sex drive.
- Ectopic pregnancy
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with norethisterone, please read the information provided with the medicine or consult your doctor or pharmacist.
Micronor should be used with caution in:
- Women who are going to have major surgery with prolonged immobilisation.
- Women with a blood clot in a vein, e.g. in the legs (deep vein thrombosis) or the lungs (pulmonary embolism), or a history of this.
- Women with disorders that increase the risk of blood clots in the veins, e.g. antiphospholipid syndrome, antithrombin deficiency or factor V Leiden.
- Women with a history of serious disease of the arteries, e.g. that has caused a stroke, angina or heart attack.
- Women with multiple risk factors for heart disease, such as diabetes, high blood pressure, smoking, high cholesterol levels, obesity.
- Women with a long-term condition called systemic lupus erythematosus (SLE).
- Women with an undiagnosed breast lump or gene mutations that are associated with breast cancer, e.g. BRCA1.
- Women with active liver disease, e.g. liver cancer, severe liver cirrhosis.
- Women with a history of liver disease when liver function has not returned to normal.
- Gallbladder disease.
- Women with a history of jaundice or itching caused by previous use of an oral contraceptive.
- Women with inflammatory bowel disease, e.g. Crohn's disease or ulcerative colitis.
- Women with a history of migraines.
- Women with a history of irregular brown patches appearing on the skin, usually of the face, during pregnancy or previous use of a contraceptive pill (chloasma). Women with a tendency to this condition should minimise their exposure to the sun or UV light while taking this contraceptive.
Miconor should NOT be used in:
- Women with abnormal vaginal bleeding, the cause of which has not yet been diagnosed.
- Women with breast cancer or a history of breast cancer (although the mini pill can be used if you have been free of cancer for five years and you don’t want to use non-hormonal methods of contraception).
- Hereditary blood disorders called acute porphyrias.
- Micronor tablets contain lactose and should not be taken by women with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency, or glucose-galactose malabsorption.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using Miconor and inform your doctor or pharmacist immediately.