Period delay

Medical information

Written and reviewed by a team of doctors. Dr Fox is regulated by the CQC & GPhC.

How period delay tablets works

Provera 10mg and norethisterone 5mg tablets can be taken three times daily to delay periods. Start tablets at least 3 days before the start of a period and continue for as long as needed. A period bleed will normally start 2-3 days, and possibly longer, after stopping the tablets.

The balance of hormones changes during the menstrual cycle. During the time Provera or norethisterone tablets are being taken a period (shedding of the womb lining) will be delayed.

Women currently taking a contraceptive pill should not use norethisterone to delay their periods. There is more information about delaying periods when taking contraceptive pills on the NHS page How can I delay my period?

Provera and norethisterone are not contraceptives and will not prevent pregnancy.

Length of treatment

Dr Fox can supply sufficient Provera or norethisterone tablets to delay a period for up to 17 days, a maximum of 60 tablets. If period delay of less than 17 days is required, the tablets are taken for fewer days and fewer tablets are required.

Taking tablets to delay periods is for occasional use only and should not be requested more than once in 3 months (four times per year). If period delay is needed more frequently or for longer, consult your own GP. Often using a form of hormonal contraceptive can be an effective period control, with many contraceptives reducing or stopping periods completely.

Patients MUST read manufacturer's patient information leaflets (links below) supplied with tablets.

Other medications - interactions

There are a few medications which can interact with Provera or norethisterone. This may make either medication less effective. Checks are carried out in the online consultation.

Possible side effects

As with all medications, Provera (medroxyprogesterone) and norethisterone can cause side effects, although these are usually not troublesome. Further information about side effects can be found in manufacturer's patient information leaflets supplied in medicine packs.

Provera 10mg side effects

Provera side-effects are usually not troublesome at the doses used for period delay. They most commonly include headache, nausea or feeling sick, and unexpected or unusual vaginal bleeding or spotting.

Norethisterone 5mg side effects

The most commonly reported side effects are bloating, breast tenderness, and loss of libido. Side effects are more likely if norethisterone is taken long term, rather than in a short course to delay periods.

Some women taking norethisterone experience fluid retention which can worsen pre-existing migraine, epilepsy, blood pressure, and asthma.

Very rare sensitivity reactions

Very rarely, Provera and norethisterone may cause a severe allergic reaction. Sudden onset of some or all of the following require emergency treatment (telephone 999 in the UK):

• Wheezing.
• Difficulty breathing.
• Feeling faint.
• Swelling of the face or tongue.
• Swelling of the hands and feet.
• Intense itchy skin rash.

Risk of blood clots (Venous Thromboembolism)

All women have a small chance of having a blood clot in the veins of the legs or in the lungs or other parts of the body. The risk of a clot is very slightly increased if norethisterone is being taken. There is much less increased risk when taking Provera.

Dr Fox cannot prescribe Provera or norethisterone if the following apply, as they also increase the risk of blood clots:

• Very overweight.
• Previous blood clot in the veins or lungs.
• Relatives have had blood clots.
• Immobility for long periods of time, e.g. after an operation, or during a long haul flight (6+ hours).
• After serious injury or major surgery.
• History of repeated miscarriage.

In about 10% of women there may be light spotting or bleeding the longer the cycle is extended.

Dr Fox supplies period delay tablets on prescription – you are required to answer a short medical questionnaire before your order can be completed.

Authored 17 November 2012 by Dr Tony Steele
MB ChB Sheffield University 1983. Former hospital doctor and GP.

Reviewed by Dr C. Pugh, Dr A. Wood, Dr B. Babor, Dr P. Hunt
Last reviewed 04 August 2021
Last updated 15 October 2021

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