Combined Pill

The combined pill contraceptive contains artificial versions of both oestrogen and progesterone. Often referred to simply as ‘the pill’, it is a common type of contraception that comes in the form of a small tablet.  


How the combined pill works

By releasing oestrogen and progestogen (synthetic progesterone) into the bloodstream, the combined pill prevents pregnancy in three ways:

  • It prevents ovulation (the release of an egg from the ovaries).
  • It thickens the mucus at the neck of the womb, making it harder for sperm to get through and fertilise an egg.
  • It thins the womb’s lining, making it more difficult for a fertilised egg to implant itself and grow.

How to take the combined pill

The two combined pill types that are commonly available are the 21-day pill and the everyday pill. There is a small difference in how you take them, so it is important to know which type of pill you’re taking. If you’re unsure, read the patient information leaflet or ask your pharmacist for advice.

As the name suggests, the everyday pill is to be taken every day, with no break between packets. These packs include 7 placebo pills that don’t contain any hormones and therefore work similarly to not taking a pill at all. The 21-day pill, on the other hand, is taken every day for 21 days followed by a 7-day break.

Regardless of which type of combined pill you take, you need to remember to take the pill at the same time every day. This helps to ensure your body always has the correct levels of oestrogen and progestogen to protect you from pregnancy.

Starting the combined pill

You can start taking the combined pill at any time during your menstrual cycle, but when you start may impact what you need to do. How to start the combined pill will also vary if you have recently given birth, are breastfeeding, or have experienced an abortion or miscarriage.

To ensure that you follow the correct guidance for starting your combined contraceptive pill you should always refer to the patient information leaflet that can be found inside your pill packet. Alternatively, speak with your GP or other healthcare professional.

What to do if you forget to take the combined pill 

If you forget to take the combined pill, or take it late, what you need to do depends on how long it has been since you were supposed to take it, the type of combined pill you are taking and where you are in the pack.

To ensure you have the correct information for what to do if you miss a combined pill, you should check the patient information leaflet that is contained within your pill packet. If you are still unsure, you should ask to speak to a healthcare professional.

Sickness and diarrhoea

Being sick or having diarrhoea can prevent the combined pill from working. If you vomit within 3 hours of taking your pill, take another and take the next pill at the normal time. If vomiting continues, you’ll need to use an alternative form of contraception as well as your pill until you’ve gone 7 days without being sick.

If you are suffering from severe diarrhoea, you’ll need additional contraception while you’re experiencing symptoms and for 2 days afterwards as well.  

Remember to check the patient information leaflet that is contained within your pill packet. If you are still unsure, you should ask to speak to a healthcare professional.

Who can take the combined pill?

The combined pill is not appropriate for everyone. It may not be the right choice for you if you:

  • Smoke or stopped smoking less than 12 months previously and are 35 or older
  • Are pregnant
  • Are very overweight
  • Take certain medications
  • Have or have had heart abnormalities, strokes or blood clots (or if a family member has aged under 45)
  • Have or have had breast cancer
  • Experience severe migraines, particularly if you get them with aura symptoms
  • Have had diabetes for over 20 years or with complications
  • Have had gallbladder or liver disease


If the above criteria don’t apply to you, you may be able to take the combined pill. Consult a pharmacist for advice if you’re unsure which type of contraception is right for you

How effective is the combined pill?

If taken correctly - as described above - the combined pill is thought to be over 99% effective for pregnancy prevention. In other words, fewer than 1 in 100 women whose chosen method of contraception is the combined pill alone will get pregnant in 1 year.

However, some medications can interfere with your contraceptive pill, including two types of antibiotics, as well as enzyme-inducing medications such as certain epilepsy drugs and St John’s Wort. To make sure none of the medications you take interfere with your birth control pill, speak to a pharmacist.

Common side effects of the combined pill

Combined pill side effects are usually temporary and generally clear up after a few months of starting the pill. However, you may experience side effects that come and go alongside your menstrual cycle. Here are some of the side effects the combined pill may cause:

  • Increased blood pressure
  • Headaches
  • Mood swings
  • Nausea
  • Tender breasts
  • Spotting or breakthrough bleeding (typically in the first few months of use)

The combined pill may also cause side effects that some people may see as an advantage such as lighter periods and relief of period pain.

Risks of taking the combined pill

Taking the combined pill is associated with an increased risk of certain conditions developing. However, this increased risk is small.

  • Blood clots

Oestrogen can cause your blood to clot more easily, which could lead to conditions such as deep vein thrombosis (DVT). The likelihood of getting a blood clot is small, and your doctor will assess the risk factors before prescribing you the combined pill. If they think the risk is too great, they will likely recommend other types of contraception .

  • Cancer

It is thought that the combined pill can also cause an increased risk of breast or cervical cancer. On the other hand, progesterone is considered to decrease the risk of endometrial cancer and oestrogen may decrease the risk of colon cancer. Usually, your risk of cervical or breast cancer will go back down to its normal level ten years after you stop taking the pill.

Where to get the combined pill

You can get the combined pill from a number of different places, including sexual health clinics, community contraception clinics, GP surgeries, online, some genitourinary medicine clinics and some young people's services.