The main points
- The Depo injection contains a hormone that is similar to the naturally occurring progesterone made by a woman’s ovaries.
- When used as instructed, your chances of becoming pregnant are less than 0.5 per cent.
- Nothing interferes with Depo working as a contraceptive. Its effects wear off with time.
What is Depo-Provera?
Depo is short for Depo-Provera® or Depo-Ralovera®. It contains a hormone that is similar to the naturally occurring progesterone made by a woman’s ovaries.
How effective is it?
When you use Depo as instructed, your chances of becoming pregnant are less than 0.5 per cent.
Allowing for mistakes (late injections), Depo is 94% effective. This means that if 100 women used Depo for a year, a maximum of six would become pregnant.
How does it work?
- It stops the body from releasing an ovum (egg) each month.
- It thickens the mucus in the cervix (the entrance to the womb), preventing sperm from getting through.
How do I use it?
You usually have an injection every 12 weeks. It is safe to have the injection up to two weeks early or late.
How quickly does it start working?
Up to 7 days.
What stops it from working?
Nothing interferes with Depo working as a contraceptive. Its effects wear off with time.
What are the advantages?
- Depo is highly effective and inexpensive.
- You don’t have to remember to take a pill every day.
- Bleeding may be lighter and less painful or may stop completely.
- It may be suitable for women unable to use contraception containing oestrogen.
- It’s a very private method of contraception: No one can find out about it unless you tell them.
- It will not be affected if you have diarrhoea or vomiting or are taking any medications.
What are the side effects and disadvantages?
- As one injection of Depo lasts for up to 14 weeks, side effects may last for this time or longer.
- All women given Depo will experience a change in their bleeding pattern.
- About 50% will stop having periods completely
- About 20% will have occasional bleeding or spotting
- About 30% will bleed or spot more than 50% of days
- The bleeding tends to become less frequent with time. Treatments are available.
- Around 20% of women gain weight.
- Depo causes a small loss of bone density (thinning of the bones). This should be recovered once injections are stopped.
- Other possible side effects include headaches, depression, anxiety and loss of interest in sex.
- Once injected, Depo cannot be reversed and it may take months for its full effect to wear off. If you want to become pregnant, there may be some delay as a result.
- Depo will not protect you against sexually transmissible infections (STIs).
Who shouldn’t use Depo?
Women who have breast cancer should not use Depo.
Usually, women who have had or are at a high risk of having a heart attack or stroke.
Is it for me?
Depo may be right for you if you:
- want a method that’s ‘fit and forget’
- want a method of contraception that’s private
- want a very effective method
- find it hard to remember to take a tablet every day
- don’t mind some bleeding irregularity
- have painful periods
- have trouble taking oestrogen
- are taking regular medications that interfere with the Pill.
What if I become pregnant?
There is no evidence that Depo can harm a pregnancy. You may safely choose to continue with the pregnancy or have an abortion.
What happens if I’m late for my injection?
If it has been 14 weeks or more since your last injection, use condoms until your next injection.
Can I use Depo while I’m breastfeeding?
Depo is considered completely safe once the baby is six weeks or older. Before this time, Depo can still be used, particularly if other methods aren’t suitable.
You should discuss any further questions with your doctor or call your local family planning clinic.
If needed, emergency contraception is available from pharmacies without a doctor’s prescription. See the FPV Emergency Contraception pamphlet for more information.
Where to get more information, support or advcie
- Contact your local doctor (GP)
- Contact Family Planning Victoria's clinics
- Visit Better Health Channel