What is injectable contraception?
It’s a form of contraception that is injected into a muscle (usually buttock or upper arm) to stop pregnancy by releasing progestogen into the body.
The brands available in Australia are:
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 opening of the uterus thicker so sperm can’t get through
- changing the lining of the uterus so a fertilised egg can’t take hold
How effective is it?
It is a very effective method of contraception (99.7%).
Where do I get the injection?
You need to make an appointment with your local doctor, SHine SA or community health clinic to discuss whether this method is a good choice for you.
When can it be given?
Injectable contraception should not be used if there is any risk of you currently being pregnant.
It can be given 6 weeks after having a baby if fully breastfeeding, or 3 weeks if not.
When does it start working?
It’s immediately effective when injected:
- during the first 5 days of your menstrual cycle where day one is the first day of your period
- 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 not effective until after 7 days if it is given at any other time. Other contraceptive measures such as condoms should be used for these 7 days.
How long does it last?
It is effective as a contraceptive for 3 months. It needs to be given regularly at 3-monthly intervals to maintain effectiveness. If you are late in getting your next injection you will need to use condoms until you get the injection.
When will I be fertile again?
Sometimes the hormone may stay in the body for more than 3 months 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 several months but you can get pregnant before your period returns, so continue to use other contraception as needed. Most women will be fertile within 8-12 months from the last injection and there is no permanent effect on fertility.
What does it cost?
On prescription it’s about $20 or if you have a Health Care Card it’s about $6.
What are the side effects?
The injection cannot be removed from your body and any side effects may continue for three months or longer.
Side effects include the following:
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.
You may experience weight gain as the injection may increase your appetite.
Headaches, breast pain and mood changes
These symptoms can occur. They usually go away after the first few weeks, but if they persist seek medical advice.
There have been some concerns with the way injectable contraception may decrease bone density during its use. This has been a concern with women under 18 and over 45 but no clinically significant problems have been identified. The World Health Organization 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. For women outside this age group, the benefits of using this contraception still outweigh the risks.
Who could use injectable contraception?
It’s suitable for women who:
- want a safe and very effective method of avoiding pregnancy and don’t mind having a regular injection
- 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
- are on medication that increases liver enzymes
- have certain medical conditions and may benefit from using it (discuss this with your doctor)
Who should NOT use the injection?
The injection should not be used by women who:
- are pregnant or want to get pregnant in the near future
- have unexplained vaginal bleeding
- have severe liver disease