The morning-after pill and menstruation: effects on the menstrual cycle

How does the morning-after pill work? How do I take it? Who can take it? What is it used for? Does it delay menstruation? Does it cause side effects in women? We answer all your questions in this article.


What is the morning-after pill?

The morning-after pill is an emergency contraception in tablet form. Emergency contraception is used to prevent an unwanted pregnancy. It is used in the event of a condom breakage, a forgotten pill or other situation. It should not be used as a contraceptive, or as a regular period pill, it is only a backup solution.
It only acts by blocking ovulation. If ovulation does not occur, there is no risk of getting pregnant since no egg equals no fertilization. But, if it has already taken place and fertilization has occurred, it will not be useful. It is therefore not an abortion pill.

There are several types of pills:

  • one with levonorgestrel that can act up to 72 hours (3 days) after unprotected or poorly protected sex, called Norlevo
  • one with ulipristal acetate, which can be taken up to 120 hours (within 5 days) afterwards, called the morning-after pill or Ellaone

To improve its effectiveness, it should be taken as soon as possible after risky sex, within the first 12 hours. The sooner the medication is taken, the faster the contraceptive effect will be.
In the first 24 hours, the levonorgestrel pill is about 95% effective, then the effectiveness drops to 85% if taken on the second day, and then to 58%.
For the day-after pill, the effectiveness is 99% if taken within 24 hours of the risky intercourse, then it drops to 98% in the next 4 days.
Since it is not 100% effective, it is recommended that a pregnancy test be taken 2 or 3 weeks after the risk intercourse to ensure that it has worked.

What are the effects of the morning-after pill on menstruation?

Because it is a hormone-based emergency contraceptive, it will affect the body and how it functions. Morning after pill and late period, morning after pill and early period? We explain you.

Modification of the menstrual cycle

As explained above, the morning-after pill works by blocking ovulation. This obviously disrupts the different menstrual phases. As a result, since it is blocked, it can be difficult to predict the date of the next ovulation and therefore the date of the next menstruation. The cycle must be restarted to have another ovulatory phase. This disruption causes other consequences, but all of them are harmless!

Some women will, for example, have :

  • bleeding
  • nausea
  • stomach aches

Other effects have been reported such as:

  • headaches and dizziness
  • breast tension

It can be given to any person. There are no contraindications to this method of contraception.


Bleeding after taking the morning-after pill

It is very common to have bleeding after using this emergency contraception, so don't worry. On the other hand, when your next blood loss arrives, you must be careful that it is a real menstrual flow, and not bleeding that can also occur at the beginning of a pregnancy.

Premature arrival of menstruation

Just after taking the morning-after pill, bleeding can occur. This is because it blocks ovulation, which, by definition, disrupts the hormonal cycle.
To be sure that it has worked, it is recommended that you take a pregnancy test within 3 weeks of taking it. It does not cause early menstruation, which is actually blood loss due to the intake. On the other hand, it can delay them.

Can the morning-after pill delay the onset of menstruation?

By blocking ovulation, it modifies the cycle. Menstruation can therefore be delayed. However, if you notice a delay in your menstrual flow, it is preferable to take a pregnancy test to check that you are not pregnant, since it is not 100% effective.

What should I do if my period does not arrive after taking a morning-after pill?

Take a pregnancy test 3 weeks after taking it. As explained before, it can delay menstruation, but if it still does not arrive, consult your doctor or gynecologist who will be able to guide you. A blood test is also a reliable way to verify that you are not pregnant.

No matter what your situation is, whether you want to get pregnant or not, remember that no one can judge your sexuality and your willingness to take a contraceptive.


FAQs about the morning-after pill and menstruation

When does my period come after taking the morning-after pill?

After taking this emergency contraception, the body is turned upside down. Menstruation can therefore be late. However, if your period is too late, consult your health care professional, as it may be a pregnancy.

Can the morning-after pill trigger a period?

Yes, it can cause bleeding in the days following the intake. Do not worry, this is completely normal, the body is only disturbed.

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