Reviewed by Dr Samantha Miller MB ChB
(2017, University of Glasgow)
GMC number: 7561464
Information last reviewed 03/03/2021
Norethisterone is a hormone that can be taken to delay your period. This is for times when having your period would be inconvenient, for example during a wedding, holiday or sporting competition. It is also sometimes prescribed to ease period problems and help endometriosis.
Norethisterone essentially works by making your body think that you are pregnant to prevent the womb lining from breaking down and exiting as period blood. Norethisterone is a synthetic version of the sex hormone progesterone. When progesterone levels are high, this causes the lining of the womb to thicken, in preparation for a fertilised egg to implant. Progesterone levels usually drop when fertilisation doesn't occur, causing your period to happen. When you take norethisterone, the progesterone levels remain high, leaving the womb lining intact until you stop taking it.
How long you take norethisterone for depends on why you are taking it. For period delay, you can take it for up to 20 days. If you have been prescribed norethisterone for another reason e.g. treating painful, heavy periods or endometriosis then follow your doctor's instructions. You’ll often take it for 3–6 months in these cases.
Dose |
1 tablet three times per day, for a maximum of 20 days, starting two days before your period is due |
Type of Medicine |
Progestin |
Mechanism |
Binds to progesterone receptors, delaying ovulation |
Available Size |
30 or 60 tablets |
Available Strengths |
5mg |
Active Ingredient |
Norethisterone |
Price |
From 37p per tablet |
Side Effects |
Can include headaches, nausea, spotting or breakthrough bleeding, fatigue, dizziness, insomnia, nervousness, confusion |
5mg of norethisterone is the active ingredient.
The inactive ingredients are lactose, maize starch and magnesium stearate.
Please note: Different brands of generic norethisterone may contain different inactive ingredients than those listed here.
To delay your period, you should start taking norethisterone 3 days before your period is due. The tablets should be taken 3 times a day for a maximum of 20 days (including the 3 days before your period). Once you stop taking them, your period should return 3 days after. Always follow the instructions given by your doctor, because how you take norethisterone depends on why you are taking it.
If you are taking the combined contraceptive pill then there is no need to take norethisterone. You can delay your period by skipping the seven-day break and running two packs together. You can take norethisterone along with the progestogen-only pill (mini pill) however. Your doctor will need to assess whether or not the combination is suitable for you, as there are certain risk factors involved in taking norethisterone such as blood clots and interactions with other medicines.
Common side effects include:
You may also experience:
If you experience any of the following side effects you should stop taking Norethisterone right away and see your doctor as soon as possible:
Norethisterone is not suitable for women who:
Extra care should be taken if you:
If you have any of the aforementioned conditions, speak with your healthcare provider.
The following medicines can interfere with the way Norethisterone works:
Drinking alcohol while you are on norethisterone will not produce any adverse effects.
Norethisterone is the generic name for the medication, Utovlan is a specific brand of norethisterone. Both work in the same way and produce the same possible side effects.
Both the contraceptive pill and norethisterone contain synthetic versions of the progesterone hormone. Which method is best will depend on your own circumstances and your current method of contraception. If you are already on the combined pill then it's very easy to delay your period. Simply skip the pill-free week and start a new pack the day after you reach the end of your current pack. If you wish to delay your period for a one-off occasion and don't have time to plan ahead, then norethisterone may be the best option.
Both methods have the side effect of breakthrough bleeding, so neither method will 100% guarantee you will have no bleeding on a particular day.
Norethisterone is not a contraceptive pill and cannot be used to prevent pregnancy. It should always be used in conjunction with your preferred method of contraception. If you are on the combined pill then this can be used on its own to delay your period. Ask your doctor for advice if you are taking the progestogen-only pill and want to delay your period using norethisterone.
Norethisterone is generally safe to use occasionally. However, it should not be used continuously and it is not suitable for everyone. Women who have a history of blood clots may be at risk and your doctor will check your medical history to ensure that Norethisterone is safe for you to use.
There is no way to stop your period once it has started. Norethisterone will only work if you take it before your period is due to prevent it from happening.
Norethisterone may affect your fertility while you are taking it. If you are trying to get pregnant then norethisterone may not be suitable for you to use. Norethisterone does not affect your long-term fertility.
We’re a fully regulated pharmacy, with qualified doctors and happy customers
Quick and discreet
Excellent service and exceptional delivery - will use again
Toni