• It is possible to postpone menstruation by using a progestogen.
• It is preferable to alter the time of menstruation before a journey or other event and not during it (thus avoiding the need to take medication during a journey).
• Women on combination contraceptive pills use these for altering the time of menstruation.

• The safety of progestogen during early pregnancy is not known. Pregnancy is therefore a contraindication. Contraception (IUD, condom, abstinence) must be used during the treatment.

Products

• Norethisterone
  • 5 mg twice daily (three times daily if spotting occurs) for a maximum of 14 days. Treatment is started at least three days before anticipated onset of menstruation. Bleeding starts 2–3 days after cessation of treatment.
• Lynestrenol
  • 5 mg daily (increase dose to 10 mg in the evening if spotting occurs)
  • Used also when a longer period of amenorrhoea (over 14 days) is desired.
    • 10 mg in the evening. Treatment is started 4–5 days before anticipated onset of menstruation. Treatment is continued as long as amenorrhoea is required. If breakthrough bleeding occurs, the dose can be increased to 15 mg per day for 3–5 days.

• Users of monophasic combined oral contraceptives can continue taking the tablets from the next strip, omitting the usual tablet-free period.
  • It is possible to continue taking the tablets without a break for as long as amenorrhoea is required, for example two entire strips could be taken one after the other followed by a 7-day tablet-free period.
  • Note! In some modern preparations the tablet-free period has been replaced with the intake of placebo pills: these should be omitted and a new strip started in order to postpone menstruation.
  • Bleeding starts 2–4 days after the last tablet. After a 7-day break the product can be used as usual.
• Users of sequential, biphasic or triphasic combined oral contraceptives can continue to take the tablets as described above but only the last 10 pills from a new strip are used as they contain more progestogen. This will prevent the onset of menstruation.
• The amount of progestogen in the oral progestogen-only contraceptives ("minipill”) is too small to be relied on to postpone menstruation. Users of these can alter the time of menstruation preferably by using 2 pills a day for the desired time. Norethisterone may also be used as described above, or one may switch to combined oral contraceptives, if there are no contraindications.
• Users of hormonal IUD can alter the time of menstruation by using additionally progesterone-only contraceptives (e.g. pills containing 30 µg of levonorgestrel, 2 pills a day) or, provided that there are no contraindications, a monophasic combined oral contraceptive containing 0.15 mg of levonorgestrel and 30 µg of ethinyloestradiol.