Combined Oral Contraception (COC)
The combined pill is usually just called the pill. It contains two hormones - oestrogen and progesterone.
How effective is it?
If the pill is taken according to the instructions it is over 99% effective.
This means that less than 1 woman in a 100 will get pregnant in a year.
How does it work?
The main way the pill works is to stop the ovaries from releasing an egg each month (ovulation).
Where can I get the pill?
Can anyone use the pill?
Not everyone can use the combined pill. Although there are some medical conditions that would mean you should not take the pill, decisions often depend on a combination of age, smoking, the severity of any medical condition, whether there are other health problems and sometimes your family history of illness. Each woman’s situation is different and your doctor or nurse will be able to advise you.
Conditions which may mean you should not use the combined pill.
- You are breast feeding and your baby is less than 6 weeks old
- You are 35 or older and smoke
- Migraine that develops whilst on the pill
- Migraine with aura symptoms
- You have had at any time a blood clot in a vein or artery
- You have a close relative who has had a blood clot in a vein under the age of 45
- You have a disorder of blood clotting
- You have certain types of heart abnormalities, previous stroke, problems with your circulation or high blood pressure
- You have had breast cancer
- You have had certain types of liver or gall bladder disease
- You have had diabetes for a long time or have complications with it
- Obesity (BMI 35 or above)
- You have antiphospholipid antibodies
- You have prolonged immobility e.g. wheelchair use or after major surgery etc.
Many women who cannot take the combined pill are often able to use contraception which only contains the hormone progesterone. This can be taken as the progesterone only pill, implant, injection or hormone coil. There is also contraception that doesn’t contain any hormones such as a copper coil, condoms and diaphragms.
How old do I have to be to start the pill?
Once your periods have started you can take the pill. Some young women take the pill who are not having sex but need help with their periods.
Can I only take the pill for a certain length of time or have to stop at a certain age?
If you are well on the pill and nothing changes in your own or family medical history then there would be no reason to stop the pill. In fact if you are healthy, do not smoke and there are no medical reasons for you not to take the pill you could take it until the age of 50.
What are the advantages of the pill?
Some of the good things about the pill are:
- Usually makes your periods regular, lighter and less painful
- May help with premenstrual tension
- Reduces the risk of cancer of the womb, ovary and bowel
What are the disadvantages of the pill?
- When you start the pill you may get headaches, nausea, breast tenderness, mood changes and some bleeding when you don‘t expect it. These normally stop within the first few months but if you are concerned or these symptoms continue then talk to a nurse or doctor about it.
- The pill may increase your blood pressure and this will be measured regularly.
- The pill does not protect you against sexually transmitted infections and many women choose to use condoms as well.
The pill can have some serious side effects which are not common. These include:
- A very small number of women may develop a blood clot which can block a vein (causing a venous thrombosis). or an artery (causing an arterial thrombosis, heart attack or stroke)
- There may be a small increase in the risk of breast and cervical cancer in women taking the pill but remember the pill does reduce the chance of cancer of the ovary and womb.
The risk of a venous thrombosis is greatest during the first year that you take the pill and if any of the following apply to you: you are very overweight, are immobile for a long period of time or use a wheelchair, have severe varicose veins or a member of your immediate family had a venous thrombosis before they were 45
The risk of arterial thrombosis is greater if you smoke, are diabetic, have high blood pressure, are very overweight, have certain sorts of migraines or a member of your immediate family had a heart attack or stroke before they were 45.
How do I take the pill?
If you start the pill on days 1 to 5 of your period then you will be protected from pregnancy immediately. Speak to a nurse or doctor for advice if you wish to start the pill at any other time.
Most pills come in foil strips of 21 tablets. Try to take it at the same time every day and take one every day until the pack is finished (21 tablets). Some pills come in strips of 28 tablets. This may be because you have what is called an Everyday Pill which contains 7 inactive pills or you have a progesteron only pill. Ask your doctor or nurse for advice if you unsure about what the pills are and how to take them.
What should I do if a forget to take a pill or start a packet late?
Missing pills or starting the packet late may make your pills less effective. The chance of pregnancy depends on when pills are missed and how many are missed.
Missing one pill anywhere in your packet or starting your new pack one day late is not a problem. Depending on which type of pill you take, missing more than one or starting the packet more than one day late may affect your contraceptive cover. To find out more, click: missed pill advice (PDF 260Kb). If you have an Everyday Pill (packs that contain inactive pills) please speak to your nurse or doctor about what to do if you miss pills.
What happens if you have sickness or diarrhoea?
What should I do if I have diarrhoea?
If you have severe diarrhoea for more than 24 hours this may make your pill less effective. Keep taking your pill at the normal time, but treat each day you have severe diarrhoea as if you had forgotten to take a pill and follow the missed pill instructions.
What should I do if I am sick?
If you vomit within 2 hours of taking a pill take another as soon as you feel well enough. As long as you are not sick again and you don't miss any pills your contraception will not be affected. Take your next pill at the normal time. If you continue to be sick, you will not be covered for contraception while you have the sickness. You should either abstain from sex or use condoms until the sickness has settled and for 7 days after the illness. This is because the pill will take 7 days to work after the vomiting has stopped.
Will other medicines affect my pill?Some medicines can make your pill less effective.
Commonly prescribed antibiotics do not affect the pill. However some drugs can reduce the effectiveness of the pill and increase the chance of getting pregnant. These include certain drugs used to treat HIV, TB and epilepsy as well as the herbal preparation 'St. John's Wort'. If you are taking any of these tablets you should speak to your doctor about the contraceptive options available to you. The emergency contraceptive pill Ella-One should be avoided if you are on hormonal contraception and if you are given Ella-One because you have missed pills you should not restart your pill for another 5 days. It will then take a further 7 days until you have effective contraception so you should abstain or use condoms for this time.