Combined Oral Contraceptive Pill

The Combined Oral Contraceptive Pill (COC pill) is a form of contraception for women. This page explains how the COC pill works and tells you how to use it.

What is the Combined Oral Contraceptive Pill (COC pill)?

The combined oral contraceptive pill.

It is a pill women take every day to prevent pregnancy. The COC pill contains the hormones oestrogen and progestogen. These are like the hormones naturally produced by women's ovaries.

How does it work?

The oestrogen and progestogen stop the eggs developing, so there is no egg released from the ovary.

How well does it work?

When used by the average person (typical use) the COC pill is 92% effective. This means eight women out of 100 will get pregnant each year.

If used perfectly i.e. taken correctly, this pill is more than 99% effective in preventing pregnancy.

Taking the COC pill continuously is better contraception/ārai hapū than typical use.

When do I take it?

There are several ways of taking the COC pill.

  1. Take 21 hormone pills and then seven inactive non-hormone pills. This is the "period option".
  2. Take hormone pills continuously, every day (skipping the inactive pills). This is the "no-period option".
  3. Take just the hormone pills for some months and every few months take the inactive pills to have a bleed. 

It is best to take this pill at the same time every day.

With the "period option" you will not be safe against becoming pregnant if you forget more than one pill within one week.

With the "no period option" you are still safe against getting pregnant unless you forget more than eight pills in a row.

What will I notice?

It depends which way you choose to take the pill/te pire.

With the "period option" you will have a monthly bleed that is usually lighter and less crampy than your usual period.

With the "no-period option'' you will not have any periods if you take a hormone pill every day. However some women get bleeding and spotting at first. This usually settles with time, or you may need to have a seven day break (see Family Planning instruction sheet).

Watch our video below on how to continuously take Norimin.

Watch our video below on how to continuously take Ava 30.

Can I still become pregnant after I stop taking the COC pill?

Your natural fertility will return as soon as you stop taking the pill. If you get pregnant while taking the COC pill, and decide to continue with your pregnancy, there is no increased risk of the baby having an abnormality.

Who can use it?

If you are healthy and do not smoke you can take the pill safely for many years.

Who should not use it?

You should not use the COC pill if:

  • you have had a heart attack, stroke or blood clot in legs or lungs
  • your parents or brothers or sisters have had a blood clot in their legs or lungs
  • you are over 35 and smoke
  • you are overweight
  • you have migraines
  • you are taking some medications, over-the-counter preparations or herbal remedies.

Check with your doctor if you are taking regular medication.

There are other reasons why this pill may not be suitable for you, such as if you have your leg in plaster or use a wheelchair.

What are the advantages?

  • It works and can be 99% effective.
  • It is convenient, simple to take and doesn’t interfere with sexual intercourse.
  • You can choose to have periods (that are usually lighter and less crampy than your usual period) or to have no periods. Tell the doctor or nurse what option you prefer.
  • It is not permanent. As soon as you stop taking the pill you can get pregnant.
  • The COC pill reduces your risk of cancer of the ovary and endometrium (lining of the womb) by 50%.
  • Some pills can improve acne.

What are the disadvantages?

  • You must remember to take it.
  • It must be taken every day whether you have sex on that day or not.
  • Some irregular bleeding may occur for a month or two after starting the pill. This does not mean the pill is less effective as long as you have not missed pills. If the bleeding continues, keep taking your pill but check with your doctor.
  • Your skin may change as dark patches on the face may occur.
  • Research does NOT show that the pill causes weight gain, headaches, breast tenderness, nausea or change in libido.

Are there any other side effects?

Serious side effects are rare. A large study which followed COC pill users for 39 years found they were less likely to die than women who did not use the pill.

Smoking greatly increases your risk of stroke or heart attack. If you don’t smoke you are unlikely to get either of these serious problems.

Pill use can increase the risk of blood clots in the leg from 2 in 10,000 women per year to possibly more than eight times that rate with some pills.

The following may suggest a serious problem, so contact your doctor if you:

  • get sudden chest pain (may be a heart attack)
  • cough up blood (may be a blood clot in the lung)
  • become breathless (may be a blood clot in the lung)
  • have pain in the lower leg (may be a blood clot)
  • have a severe headache (may be a migraine, stroke).

Does the COC pill cause cancer?

Cancer of the breast

Research suggests that even if there is any risk of breast cancer it is small. If you have someone in your family who has had breast cancer, discuss this with your healthcare provider

Cancer of the cervix

Women who have been on the pill for five or more years and who carry certain types of wart virus, which are the main cause of cervical cancer, have a slight increase in the risk of cervical cancer. All women on the pill should have cervical smears as recommended by the New Zealand Cervical Screening Programme.

Cancer of the ovary

The risk is reduced by 50% and there is still a lower risk more than 30 years after stopping the pill

Cancer of the endometrium

This cancer is in the lining of the womb. The risk is reduced by 50% and there is still a lower risk more than 15 years after stopping the pill.

Does this pill protect you from sexually transmissible infections (STIs)?

No. You need to use condoms (and lubricant) as well to protect against STIs.

Family Planning has clinics located throughout New Zealand. Use the clinic finder to find your nearest clinic.

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