Contraception - injections

About the contraceptive injection

Hormonal contraception is available in several forms, one of which is the slow release injection.

The contraceptive injection (also called Depo) is an injection of the hormone progestogen. Progestogen is like the hormone produced by the ovaries. It is sold as Depo-Provera® or Depo-Ralovera® in Australia.

Other types of hormonal contraception include:

• contraceptive implant
• hormonal IUD
• oral tablets (the combined pill and the progestogen only (mini) pill)
• vaginal ring.

Contraceptive injections are very effective if used the right way. When choosing the method of contraception that best suits you, it can help to talk to a doctor or nurse about your options.

Effectiveness of the contraceptive injection

Each injection is more than 99% effective at preventing pregnancy and lasts for 12 to 14 weeks.

Its effectiveness will be reduced if the injection is delayed.

How to use the contraceptive injection

A doctor or nurse will inject Depo into the muscle tissue in your arm or bottom.

For continued contraceptive protection this should be repeated every 12 to 14 weeks.

How the contraceptive injection works

The injection works by preventing the ovaries from releasing an egg each month. It also thickens the fluid around the cervix (opening to the uterus or womb). This helps to prevent the sperm from reaching the egg.

When it is first injected, or after a break, it can take up to 7 days to start working to prevent pregnancy.

Where to get the contraceptive injection

Your doctor or nurse practitioner will write you a script and you can get Depo from your pharmacy.

You will need to return to the clinic to have it injected. It is cheaper if you have a healthcare card.

Advantages of the contraceptive injection

Advantages of the contraceptive injection are:

• it is very effective
• most users have no vaginal bleeding at all or very light bleeding
• periods may be less painful
• it lasts for 12 to 14 weeks
• it can be used while breastfeeding
• no medications stop it from working
• it is another choice if you have difficulty taking the hormone oestrogen. ‘The pill’ (also known as the combined pill) and the vaginal ring contain oestrogen and progestogen. Depo only contains progestogen.

Side effects from using the contraceptive injection

Side effects of the contraceptive injection may include:

• Your menstrual bleeding pattern (period) will change. It might be more often or irregular (at odd times). Around 50 to 60%of women will have no bleeding at all (this is not harmful to the body). Episodes of prolonged or frequent bleeding may get better with time. Some medications can help with this bleeding – speak to your doctor or nurse.
• Around 20% of users will gain weight.
• There is a small drop in your bone density (your bones become thinner). This is not thought to be harmful, as your bone density returns once you stop the injections.

Other possible side effects for a small number of users can include:

• headaches
• bloating
• changes to your skin
• sore or tender breasts
• mood changes.

These side effects often settle with time.

Contraceptive injection and serious health problems

There are no known serious health risks from having the contraceptive injection.

Suitability of the contraceptive injection

The contraceptive injection might not be a good option if you:

• have plans to become pregnant soon
• have been treated for breast cancer
• have severe liver disease
• have risk factors for heart disease (such as smoking or diabetes)
• have previously had a heart attack or a stroke.

What stops the contraceptive injection from working

Depo might not work if the next injection is delayed after the recommended period of time.

To prevent this happening, it may be helpful to write down the date or enter a reminder in your phone for when your next injection is due.

If you are late having the contraceptive injection

Once it is more than 14 weeks since your last injection, use condoms until you can have your next injection.

Keep using condoms for another 7 days after the injection.

If you get pregnant while using the contraceptive injection

The injection is not known to harm a pregnancy.

It is safe to continue the pregnancy (and stop having the injections) or to have an abortion.

Contraceptive injection after having a baby

Depo can be given straight after you give birth, whether or not you’re breastfeeding, but other types of contraception might be a better choice until the baby is 6 weeks old because it may cause heavy or irregular bleeding.

Talk to your doctor about which contraceptive choice is most suitable for you at this time.

Read more about contraception after giving birth.

Contraceptive injection and pregnancy

The effects of the contraception injection can take some months to wear off.

It might take a while to become pregnant.

Further information about the contraceptive injection

The contraceptive injection does not protect you from sexually transmissible infections (STIs). Condoms provide the best available protection from sexually transmissible infections (STIs).

The contraceptive injection is one of many types of contraception. Read about other contraceptive options.

Where to get help

• Your GP (doctor)
• Pharmacist
• Many community health services and some public hospitals will have a family planning clinic, a sexual health clinic or a women’s health clinic providing contraception
• 1800 My Options Tel. 1800 696 784 – for information about contraception, pregnancy options and sexual health in Victoria
• Sexual Health Victoria (SHV) – book an appointment online or call Melbourne CBD Clinic: Tel. (03) 9660 4700, Box Hill Clinic: Tel. (03) 9257 0100 or (free call): Tel. 1800 013 952. These services are youth friendly