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Side effects and risks of the combined pill

Common side effects of the combined pill

You may have some side effects when you first start taking the combined contraceptive pill (also called the pill).

Bleeding between periods (breakthrough bleeding) or changes to your periods are common in the first few months.

Taking the pill can cause high blood pressure in a small number of people.

Some people report headaches, feeling sick or dizzy, and sore breasts. But there is not enough evidence to say whether this is caused by taking the pill.

For some people the pill improves period pain and other symptoms linked to periods, such as headaches.

There is no evidence that taking the pill makes you put on weight or changes your sex drive.

If you still have side effects after 3 months and they’re a problem for you, speak to a pharmacist or doctor. It may help to change to a different pill.

Risks of the combined pill

There are some other problems linked to taking the combined pill. But the chance of getting these is small.

Blood clots

The risk of getting a blood clot is very small and affects up to 1 in 1,000 people using combined hormonal contraception like the pill.

A doctor, nurse or pharmacist will check if you have certain risk factors before prescribing the pill.

There is a potential risk of:

  • a blood clot in your leg or lung
  • a blood clot causing a heart attack
  • a blood clot causing a stroke

Find out more about blood clots, including symptoms and when to get help.


Taking the pill can slightly increase your risk of getting:

But your risk of breast cancer and cervical cancer goes back to normal 10 years after you stop taking the pill.

Taking the pill can also lower your risk of getting:

Page last reviewed: 15 February 2024
Next review due: 15 February 2027