Injectable contraception
What is the injectable contraception?
It's a form of contraception that is injected into the muscle (usually buttock) to stop pregnancy by releasing progestogen into the body.
How does it work?
Progestogen is a hormone which works by:
- stopping the release of an egg by the ovary (ovulation)
- making the mucus (sticky fluid) at the entrance of the uterus thicker so sperm can't get through
- changing the lining of the uterus so a fertilised egg can't grow
How effective is it?
It is a very effective method of contraception (99.7%). The brands available in Australia are:
- Depo-Provera
- Depo-Ralovera
How do I get the injection?
You need to make an appointment with your local doctor, SHine SA or The Second Story to discuss this method and get a prescription. Once you have your prescription filled you need to return to the clinic to get the injection.
When can it be given?
Injectable contraception can be given:
- during a period or at any other time in the cycle where there's no risk of pregnancy
- six weeks after having a baby if fully breastfeeding, or three weeks after if not, or not fully, breastfeeding
When does it start working?
It's immediately effective when injected:
- during the first 5 days of a period where day one is the first day of bleeding
- while covered by other forms of hormonal contraception, e.g. the Pill, Implant etc.
- up to 7 days after having an abortion or miscarriage
The injection is effective after 7 days if it is given at any other time in the menstrual cycle. Other contraceptive measures such as condoms should be used during this time.
How long does it last?
It is effective as a contraceptive for 12 weeks. It needs to be given regularly at 12-weekly intervals to maintain effectiveness. If you are late in getting your next injection you will need to use a condom until you get the injection.
When will I be fertile again?
The hormone may persist in the body for more than 12 weeks after the last injection. This can affect menstrual cycles and delay the return of fertility. You can tell when it is out of your body because your periods will return to normal. This can take some months but you can get pregnant before your period returns. Most women will be pregnant within 18 months and there is no permanent effect on fertility.
What does it cost?
On prescription it's up to $20 or if you have a health care card it's up to $5. There may be an extra charge for your doctor appointments.
Who could use injectable contraception?
It's suitable for women who:
- want a safe and very effective method of avoiding pregnancy and prefer it to other contraceptive methods
- don't mind having no periods
- are unable to use the Pill or vaginal ring because they have problems taking the hormone oestrogen
- find it difficult to remember to take a daily pill
- are breastfeeding
- have certain medical conditions and may benefit from using it (discuss this with your doctor)
It's relatively safe for heavy smokers and diabetics.
There have been some concerns with the way injectable contraception may affect bone density. The World Health Organization (2005) recommends that there should be no restriction on the use of injectable contraception or how long it is used for among women aged 18 to 45.
With adolescents their bones are still developing until the age of 18. We are unsure about how the injectable contraception will affect bone mass. It may be used after other methods have been discussed and considered to be unsuitable or unacceptable.
With women over 45 there are theoretical concerns that they may not regain their bone mass before menopause.
However, the benefits of taking this contraception still outweigh the risks.
What are the side effects?
The injection cannot be removed from your body and any side effects may continue for twelve weeks or longer. Side effects include the following:
- Bleeding patterns
All women experience a change in bleeding patterns. With continued use the majority of women stop having periods. Some women have irregular bleeding or spotting. Heavy or continuous bleeding rarely occurs. - Weight gain
You may experience weight gain as the injection may increase your appetite. - Headaches, breast pain and mood changes
These symptoms can occur. They may go away after the initial few weeks, but if persistent seek medical advice.
Who should NOT use the injection?
Women who are pregnant or want to get pregnant within the next twelve to eighteen months, women with unexplained vaginal bleeding or women with severe liver disease should not use the injection.
Are you at risk of STIs?
The injection does not protect you against sexually transmitted infections (STIs). Practise safer sex. Condoms reduce the risk of STIs.
This information is available to download in leaflet format as Injectable contraception (PDF).