Oral hormonal contraception is more than 99 per cent effective in preventing pregnancy, when used the right way. Given mistakes that can happen, such as missing a pill or running out of pills, it is only around 91 per cent effective. More effective contraceptive options are available, including the contraceptive implant and intrauterine devices (copper or hormonal).
The two types of oral contraception that are available in Australia are the combined pill, known as ‘the pill’, and the mini pill. Both types can be bought from pharmacies with a doctor’s prescription.
When choosing the method of contraception that best suits you, it can help to talk to a doctor or nurse about your options. Different methods may suit you at different times in your life. A doctor or nurse can give you information about the benefits and risks of using oral contraception, as well as other methods of contraception.
The combined contraceptive pill
The combined pill (often referred to as ‘the pill’) contains synthetic versions of oestrogen and progesterone, which are hormones that women make naturally. It works by stopping ovulation – the process where the ovaries release an ovum (egg) each month. It also makes the fluid at the opening to the uterus thicker, stopping sperm from getting through.
If used the right way, the combined pill is more than 99 per cent effective in preventing pregnancy.
There are different types of the combined pill, including:
- pills with fixed dose combinations
- pills that vary in dose throughout the cycle
- pills that contain different types of synthetic oestrogen and progesterone.
The combined pill is packaged in either 21-day or 28-day ED (everyday) packs. All packs have at least 21 hormone (active) pills. With the 21-day packs, pills are taken for 21 days with a seven-day break. The 28-day packs also have up to seven inactive pills made of sugar, which are included to keep up the habit of taking a pill every day.
Advantages of the combined pill
Advantages of taking the combined pill include:
- It usually makes periods shorter, lighter and more regular.
- It can improve symptoms that can come with periods such as pain, mood swings and headaches.
- It lessens the risk of cancer of the ovaries and uterus.
- It can be used to safely skip periods.
- It usually improves acne.
Disadvantages of the combined pill
Disadvantages of taking the combined pill include:
- You will need to remember to take a pill every day.
- Cost can be an issue.
- You will need to be able to visit your doctor regularly to renew your prescription.
- It can cause side effects such as nausea, breast tenderness, headaches and increased appetite.
- It can lead to serious complications such as deep vein thrombosis (blood clots), heart attacks and strokes, but these are not common.
- The combined pill does not suit women who have medical conditions such as certain types of migraines, high blood pressure, severe heart conditions or liver disease.
- It is not recommended for women who are very overweight, or who smoke and are aged over 35.
- Vomiting and severe diarrhoea can stop the combined pill from being absorbed by the body.
- Some medication, such as the type used to treat epilepsy, and the herbal remedy St John’s wort, may stop the combined pill from working.
- It does not give protection from sexually transmissible infections (STIs).
Cancer concerns and the combined pill
Whether or not the combined pill increases the risk of breast cancer is not known. Experts agree that if it does increase the risk, the increase is small. There is a small increase in the risk of cancer of the cervix, but the risk of this cancer is very low in Australia.
The combined pill has been found to reduce
the risk of cancer of the ovaries and uterus and may also reduce the risk of bowel cancer.
The mini contraceptive pill
The mini pill (progestogen-only pill) contains only one hormone, a synthetic version of progesterone, which is a hormone that women make naturally. It works by making the fluid at the opening to the uterus (womb) thicker, stopping sperm from getting through. A pill has to be taken at the same time every day.
If used the right way, the mini pill is more than 99 per cent effective in preventing pregnancy, but does not work as well in younger women.
Advantages of the mini pill
Advantages of taking the mini pill include:
- It can be used by most women who cannot take medication containing oestrogen.
- It is safe to use when breastfeeding.
Disadvantages of the mini pill
Disadvantages of taking the mini pill include:
- The mini pill has to be taken within three hours of the same time every day.
- It can make bleeding unpredictable, with some women having their period more often or at odd times, bleeding between periods or not having periods at all.
- Vomiting and severe diarrhoea can stop the mini pill from being absorbed by the body.
- Some medication, such as the type used to treat epilepsy, and the natural remedy St John’s wort, can stop the mini pill from working.
- It does not give protection from STIs.
Emergency contraception , also known as ‘the morning after pill’, can be taken after
having sex to help prevent a pregnancy. Emergency contraception can be used when contraception has not worked or has not been used, such as when a condom breaks or a pill is missed, or in the case of rape.
Emergency contraception should be taken as soon as possible, ideally within 24 hours of having sex, but it still works well within 96 hours (4 days). It can be taken within 96 to 120 hours (5 days), but it will not be very effective.
The most widely used type of emergency contraception is the single pill option with only one hormone. This type contains a large dose of synthetic progesterone, which is similar to the hormone that women make naturally. Progestogen-only emergency contraception can be bought from most pharmacies without a doctor’s prescription.
Other methods of contraception
There are many contraceptive methods available in Australia. When you are choosing the method that is right for you, it is important to have access to accurate information and to talk openly about your options with your partner.
It is also important to think about how well each method works, the possible side effects, how easy it is to use and how much it costs. It is important to weigh the pros against the cons and think about how each method meets your current and future needs. The method you choose will depend on your general health, lifestyle and relationships. It can help to talk about your options with a doctor or reproductive health nurse.
Protection from sexually transmissible infections (STIs)
Oral contraception does not give protection from sexually transmissible infections (STIs). It is important to practise safer sex, as well as to prevent an unintended pregnancy. The best way to lessen the risk of STIs is to use barrier methods, such as condoms. Condoms can be used for oral, vaginal and anal sex with oral contraception to help stop infections from spreading.
Where to get help
- Your doctor
- Family Planning Victoria Tel. (03) 9257 0100 or freecall 1800 013 952
- Family Planning Victoria’s Action Centre (for people aged under 25) Tel. (03) 9660 4700 or freecall 1800 013 952
- Women’s Health Information Centre Tel. (03) 8345 3045 or 1800 442 007
- Melbourne Sexual Health Centre Tel. (03) 9341 6200 or 1800 032 017
- Community health centre
Things to remember
- Oral hormonal contraception is very effective in preventing pregnancy, when used the right way.
- The two types of oral contraception available in Australia are the combined pill, known as ‘the pill’, and the mini pill.
- Oral contraception does not give protection from sexually transmissible infections (STIs). The best way to lessen the risk of STIs is to use barrier methods such as condoms with all new sexual partners.
This page has been produced in consultation with and approved by:
Family Planning Victoria
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.