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Combined Oral Contraception - The pill

We offer advice and guidance across a range of contraception options available to you. It’s important to choose contraception that fits your situation and lifestyle

First visit

If you would like to start contraception  or continue contraception you are already taking , please make an initial doctor appointment to discuss your needs by calling us on 01 716 3134. Please have your PPS number ready to avail of the free service.

The combined contraceptive pill is a tablet that contains artificial versions of the two female hormones, oestrogen and progestogen.

It is:

  • Over 99% effective when you use the method correctly every time 
  • Over 91% effective when you don’t always use the method correctly

Contraception is now free for 17 – 31 year olds who have a PPS number.  The cost of contraceptive consultations, appointments, prescriptions, fitting and removal of coils and implants and any other costs involved are all covered.

Students who fall outside this scheme are also welcome to attend to discuss their contraceptive needs.

(opens in a new window)Please if you do not have a valid PPS number, apply for one here.

The combined pill releases the artificial form of the hormones - oestrogen and progesterone - which are absorbed into your body. 

It works by:

  • stopping ovulation (an egg being released from your ovaries)
  • thickening the mucus at the neck of the womb (uterus) so it is difficult for sperm to enter the womb 
  • thinning the lining of the womb and this prevents a fertilised egg from settling (implanting) in the womb

  • Over 99% effective when you use the method correctly every time 
  • Over 91% effective when you don’t always use the method correctly

Some advantages of the pill include:

  • it does not interrupt sex
  • it usually makes your bleeds regular, lighter and less painful
  • it reduces your risk of cancer of the ovaries, womb and colon
  • it can reduce symptoms of (opens in a new window)PMS (premenstrual syndrome)
  • it can sometimes reduce acne
  • it may protect against pelvic inflammatory disease
  • it may reduce the risk of fibroids, ovarian cysts and non-cancerous breast disease

  • If you miss a pill, or are vomiting or have severe diarrhoea, it can be less effective.
  • It is not suitable if you smoke and are over 35 years of age.
  • It is not suitable if you are obese.
  • It may not be suitable if you are breastfeeding. Check with your doctor.
  • Its effectiveness may be reduced by taking certain medications.
  • Does not protect against sexually transmitted infections

When starting the pill some women may experience: breast tenderness, skin irritation, mild 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 of using this contraceptive. There are rarely more serious side effects. Some women could develop a blood clot in the leg or lung and some may develop severe migraine.

You should see a doctor immediately if you develop any of the following symptoms:

  • Pain or swelling in the legs.
  • Severe chest pain.
  • Breathlessness or coughing up blood.
  • Bad fainting attack or collapse.
  • Unusual headaches or difficulty with speech or sight.
  • Numbness or weakness of a limb.

The pill does not have an effect on future fertility. Many women will return to their natural levels of hormone secretion  and fertility very quickly after they stop taking the pill — usually within a couple of days or weeks. However, rarely, it can sometimes take several  months for a normal cycle to return.

If there are no medical reasons why you cannot take the pill, and you do not smoke, you can take the pill until your menopause. However, the pill is not suitable for everyone. To find out whether the pill is right for you, talk to a GP, nurse or pharmacist.

The pill may not be right for you if you:

  • are pregnant
  • smoke and are 35 or older
  • stopped smoking less than a year ago and are 35 or older
  • are very overweight
  • take certain medicines

The pill may also not be right for you if you have (or have had):

  • (opens in a new window)blood clots in a vein, for example in your leg or lungs
  • stroke or any other disease that narrows the arteries
  • anyone in your close family having a blood clot under the age of 45
  • a heart abnormality or heart disease, including high blood pressure
  • severe (opens in a new window)migraines, especially with aura (warning symptoms)
  • breast cancer
  • disease of the gallbladder or liver
  • (opens in a new window)diabetes with complications or diabetes for the past 20 years

Starting on the 1st day of your period

If you start the combined pill on the 1st day of your period (day 1 of your menstrual cycle) you will be protected from pregnancy straight away. You will not need additional contraception.

Starting on the 5th day of your cycle or before

If you start the pill on the 5th day of your period or before, you will still be protected from pregnancy straight away.

Starting after the 5th day of your cycle

You will not be protected from pregnancy straight away and will need additional contraception until you have taken the pill for 7 days.

If you start the pill after the 5th day of your cycle, make sure you have not put yourself at risk of pregnancy since your last period. If you're worried you're pregnant when you start the pill, take a pregnancy test 3 weeks after the last time you had unprotected sex.

There are 4 possible options you can choose from depending on your personal preference.

  • 21/4 -take one pack of pills followed by a 4 day break, if you prefer a period every month.  This is our most usual recommendation here in UCD.
  • 63/4 -take 3 packs of pills back to back followed by a 4 day break.
  • 84/4-take 4 packs of pills back to back followed by a 4 day break.
  • Continuous (365) -take the pill every day of the year without a break.

If you are less than 12 hours late:

  • Take the missed pill as soon as you remember it and carry on with the rest of the pack as normal. No extra precautions needed.

If you are more than 12 hours late:

  • Take the missed pill as soon as you remember and carry on with the rest of the pack as normal (you may need to take two pills together). You will need to use extra precautions for the next seven days. If you have unprotected sex during this time you may need emergency contraception. If you have less than seven pills left in your pack, do not take your four day break this month. Start your new pack on the day after finishing the current pack. The withdrawal bleed will probably not occur in this case.

If you vomit within 3 hours of taking the combined pill, it may not have been fully absorbed into your bloodstream. Take another pill straight away and the next pill at your usual time.

If you continue to be sick, keep using another form of contraception until you've taken the pill again for 7 days without vomiting.

Very severe diarrhoea (6 to 8 watery poos in 24 hours) may also mean that the pill does not work properly. Keep taking your pill as normal, but use additional contraception, such as condoms, while you have diarrhoea and for 2 days after recovering.

Some medicines interact with the combined pill and it does not work properly. Some interactions are listed on this page, but it is not a complete list. If you want to check your medicines are safe to take with the combined pill, you can:

  • ask a GP, practice nurse or pharmacist
  • read the patient information leaflet that comes with your medicine


The antibiotics rifampicin and rifabutin (which can be used to treat illnesses including tuberculosis and meningitis) can reduce the effectiveness of the combined pill. Other antibiotics do not have this effect.

If you are prescribed rifampicin or rifabutin, you may be advised to change to an alternative contraceptive. If not, you will need to use additional contraception (such as condoms) while taking the antibiotic and for a short time after. Speak to a doctor or nurse for advice.

Epilepsy and HIV medications and St. John's wort

The combined pill can interact with medicines called enzyme inducers. These speed up the breakdown of hormones by your liver, reducing the effectiveness of the pill.

Examples of enzyme inducers are:

A GP or nurse may advise you to use an alternative or additional form of contraception while on this medication. 

After a miscarriage or abortion

If you have had a (opens in a new window)miscarriage or (opens in a new window)abortion, you can start the pill up to 5 days after this and you will be protected from pregnancy straight away. If you start the pill more than 5 days after the miscarriage or abortion, you'll need to use additional contraception until you have taken the pill for 7 days.

After having a baby

If you have just had a baby and are not breastfeeding, you can most likely start the pill on day 21 after the birth but you will need to check with a doctor. You will be protected against pregnancy straight away.

If you start the pill later than 21 days after giving birth, you will need additional contraception (such as condoms) for the next 7 days.

If you are breastfeeding, you're not advised to take the combined pill until 6 weeks after the birth.

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)