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Progesterone Only Contraception

The progesterone only pill does not contain oestrogen and is taken every day without a break.

It is slightly less effective than than standard combined pill and  needs to be taken correctly to given optimum contraceptive cover 

It is suitable for patients who want to avoid oestrogen or when  oestrogen is contraindicated because of medical risk factors.

Progesterone Only Contraception

How does it work? 

The main action of progestogen-only pills is to thicken the mucus in the neck of the womb. This makes it difficult for sperm to reach the egg. The progestogen-only pill sometimes stops your ovaries from releasing an egg (prevents ovulation). This is the main action of one of the newer progestogen-only pills, Cerazette. This is the reason that there are different instructions if you take a pill late for Cerazette as compared with older types of the progestogen-only pill (Noriday is the only other progestogen-only pill available in Ireland).

How much does it cost?

The progesterone only pill is  free for all 17-30 years old who have a PPS number (link)

It is is also available on prescription for other women , charges will apply

As with any contraceptive its effectiveness depends on how well the instructions are followed With perfect use the progestogen-only pill is over 99% effective meaning that less than 1 woman in 100 will become pregnant in a year.  But with less careful and consistent use, more women will get pregnant.

This pill is even more effective in women over 40 years of age. To make the pill as effective as it can be, remember:

  • To take it regularly, and at the same time each day.
  • Use another contraceptive method as well if you miss a pill or are sick, have severe diarrhea, or are taking medicines which may interfere with the pill.

  • It is a very effective method when used correctly
  • It is easy to use and does not interrupt sex
  • There are no serious side-effects
  • May help with pre-menstrual tension and painful periods
  • You can use it if you are breastfeeding
  • You can use it at any age
  • You can use it if you are over 35 and you smoke (not advised with combined pill)
  • May be an alternative for women who cannot take the combined pill

You need to remember to take the pill daily and at the same time every day or it will not work.

  • The pill does not protect you against sexually transmitted infections.
  • Your period may change in a way unacceptable to you. Some women find their periods stop completely or become irregular, light or more frequent. This may settle down and is not harmful but you may find it annoying. Speak to your doctor as changing to a different brand might help.

The progesterone only pill is suitable for women who do not want to or cannot take oestrogen for medical reasons. It is also suitable for breastfeeding mothers

Medical contraindications include active Deep Venous Thrombosis and severe liver disease

  • choose a convenient time in the day to take your first pill
  • continue to take a pill at the same time each day until the pack is finished
  • start your next pack of pills the following day – there's no break between packs of pills

You can start the progestogen-only pill at any time in your menstrual cycle

You will be covered for contraception after 2 days

Take it as soon as you remember, and take the next one at the right time. This may mean taking two pills in one day. This is not harmful.

If you take the Noriday pill more than 3 hours late, you are not protected. Continue to take your pills as soon as possible and you will be protected after 2 days of taking your pill normally. Until then, either use condoms or abstain from sex.

If you are taking Cerazette, you will be unsafe (not protected against pregnancy) if you are more than 12 hours late in taking your pill. Again, your protection against pregnancy will return after 2 days of taking the pill normally.

If you vomit within two hours of taking the pill or if you have very severe diarrhea the pill may not be effective and you should use an extra method of contraception such as a condom during the stomach upset and for two days after.

When starting the pill some women may experience: breast tenderness, spotty skin, headaches, a bloated feeling, or have some breakthrough bleeding (bleeding between periods).

Although these can be a nuisance, they are not dangerous and should disappear within the first few months using this contraceptive.

Cysts on the ovary may occur in progestogen-only pill users, but are not dangerous. These may cause pain, but often there are no symptoms. These cysts usually disappear without treatment when you stop taking the pill.

Research about the risk of breast cancer, cervical cancer and hormonal contraception is complex and contradictory. Current research suggests that users of all hormonal contraception appear to have a small increase in risk of being diagnosed with breast cancer compared to non-users of hormonal contraception. Further research is ongoing. All risks and benefits should be discussed with your doctor.

However, some other medicines may interfere with the way the pill works. These include some drugs that treat epilepsy, HIV and TB, as well as the ‘natural’ remedy St. John’s wort. You may have to use another method as well, such as the condom, while you are taking the medicines, and up to a further four weeks afterwards. If you are taking these medicines on a long term basis, oral contraceptives are probably not the best method for you. Always mention you are on the progestogen-only pill if you are prescribed any medicines.

There is a very slight chance you will become pregnant even if you use the pill correctly. However, a missed period does not always mean you are pregnant, especially if you have used the pill correctly.ª Take the next packet as normal if you think you have put yourself at risk of pregnancy or if you miss a second period see your doctor at once.

It is unlikely that taking the pill during early pregnancy will increase the risk of defects in the fetus. However, the likelihood of ectopic pregnancy is greater if you become pregnant while taking the progestogen-only pill. Although it is rare, it can be dangerous. You should see your doctor straightaway if you have sudden unexplained lower abdominal pain.

Contact UCD Student Health Service

Student Health Service, Student Centre, University College Dublin, Dublin 4
T: +353 1 716 3134 | Location Map(opens in a new window)