Norethisterone is a progestogen hormone, which helps the body maintain the womb lining. When the levels of Progestogen in the body fall, the lining of the womb is shed, and this results in a period.

It should only be used on an occasional basis and for no longer than three weeks for this purpose. It does not work as a contraceptive.

It is important that you use contraception such as condoms while taking norethisterone to avoid pregnancy, as this medication can affect fetal development. If you need advice on contraception, then speak to your nurse, doctor or family planning clinic. 

Norethisterone 5mg is taken three times a day to delay your period. It should be started 3 days before your period is due, and continued until you want your period to restart. You should normally notice your period return after 2 or 3 days once it is stopped.

Please fully read the Patient Information Leaflet that comes with the medication before starting treatment. This will contain more comprehensive information and a full list of side effects. 

Take the tablets with a drink of water either before or after meals. Aim to take your doses at the same times of day, as this will help you to remember to take them.

Norethisterone is a progesterone, however, it can have oestrogenic effects which result in an increased risk of developing blood clots (venous thromboembolism).

If you have a history of any of the following then you should NOT take norethisterone:

• if you are at risk for blood clots
• a personal history of blood clots
• a strong family history of blood clots
• if you are overweight (BMI>30)
• if you are immobile or wheelchair bound
• a carrier of thrombophilia
• if you are pregnant
• liver disease
• a history of breast cancer
• undiagnosed vaginal bleeding
• genital tract cancer
• if you are a high risk for arterial disease
• migraines with aura 

Do not take norethisterone if you are already taking the combined contraceptive pill. It is fine to take with the mini pill (Progesterone Only Pill).

The following medications interact with norethisterone and can reduce its efficacy. You should not take norethisterone if you are taking any of the following:

• St John's wort (a herbal remedy for depression and anxiety)
• The antibiotics rifampicin and rifabutin (used to treat TB and meningitis). Other antibiotics do not reduce the effectiveness of the pill.
• Epilepsy (some may be used for migraines) drugs: carbamazepine, oxcarbazepine, phenytoin, phenobarbital, primidone, and topiramate.
• Anti-retroviral medicines used to treat HIV.
• Ulipristal acetate: ellaOne (emergency contraception) and Esmya (for fibroids).

Speak to your GP or pharmacist about alternative options. 

Common side-effects include:

• bloating
• a headache
• nausea
• spotting- small amounts of vaginal bleeding

Less common side effects include:

• stomach upset
• breast discomfort
• reduced sex drive (libido)
• dizziness
• skin reactions
• fluid retention (oedema)

The side effects will often improve as the body gets used to the medication. If any of them become bothersome, then speak to your pharmacist or doctor.

If you develop any of the following symptoms, then the medication should be stopped and you must seek urgent medical advice (from your GP, Out of Hours Service, Urgent care centre, NHS 111). Call an ambulance or go to A&E if your symptoms are severe. 

• Pain or tightness in your chest.
• Difficulty in breathing
• Calf pain or swelling (signs of a blood clot)
• Vision or hearing disturbances
• Any unusually severe headaches.
• Jaundice (yellowing of your skin or the whites of your eyes)
• A significant increase in blood pressure

Please note that i-GP DOES NOT TREAT Medical Emergencies. 

How you postpone your period while taking the combined contraceptive pill will depend on the type of pill you are taking. 

If you are taking a:

• Monophasic pill (e.g., Microgynon, Cilest) start a new packet of pills straight after you finish the last pill and miss out the seven-day break. This isn't always effective at preventing a bleed.
• Everyday (ED) pill (e.g., Microgynon ED) throw away the seven inactive (dummy) pills which are at the end of your packet and start the active pills in a new packet straight away. Take all the pills in your next packet including the dummy pills. 
• Triphasic or biphasic type of pill (e.g., Binovium, Logynon) these pills have a different mix of hormones in each pill depending on which phase of pills you are in. For the contraceptive to be effective, these pills need to be taken in the correct order. Please speak to your pharmacist to check which pills can be missed out to delay your period. The other option is to change to a fixed-dose (monophasic) pill.

If you are unsure of which pill you are taking, or if you are unsure about which pills to miss out in your packet, then please speak to your GP or pharmacist for further advice. 

Avoid taking more than two packs without a break, unless your GP has said that you may. There is a risk you could experience side effects including, bloating, unexpected vaginal bleeding or stomach pains.

Contraceptive pill

You may wish to start taking the combined oral contraceptive pill if it is suitable for you and is likely to be a contraceptive choice you would like to consider. For it to be effective as an option to delay your period then you would need to start it a few weeks before your planned event to avoid having a bleed during that time. 

If you would like to start the combined oral contraceptive for the first time then it is important that you are assessed to ensure it is safe for you to take. Please see your GP or attend a family planning clinic. 

If you're switching to or starting the combined contraceptive pill, then you may be required to use additional contraception during the first few days of taking it. Please discuss this with your pharmacist or GP. 

Provera

Your GP may be able to prescribe you Provera (Medroxyprogesterone acetate) if you are at a high risk for blood clots (Venous Thromboembolism).