Contraceptive Injection - DMPA (Depo-Provera® & Depo-Ralovera®)
What Is The Contraceptive Injection?
The contraceptive injection called Depot Medroxyprogesterone Acetate (DMPA), is similar to the hormone called progesterone, which is produced in the body by the ovaries.
In Australia it is sold as Depo-Provera® and Depo-Ralovera®. Each injection of DMPA provides protection against pregnancy for 12 weeks.
How Does It Work?
The contraceptive injection mainly works by stopping the ovaries from releasing an egg (ovulation).
How Effective Is It?
The contraceptive injection is a very effective contraceptive.
It is between 99% and 94% effective which means that between one and six women in every hundred who are using the contraceptive injection will become pregnant in a year.
In practice it is more effective than the oral contraceptive pill because you only need to remember to have the injection every 12 weeks, instead of taking a pill every day.
Can Anyone Use The Contraceptive Injection?
Most women can use the contraceptive injection.
It is safe to use the contraceptive injection while you are breastfeeding, although you should be aware that small amounts of the hormone will pass to the baby in the breast milk. The contraceptive injection will not affect the quality or quantity of the breast milk.
Some women may not be advised to use the contraceptive injection. This includes women:
- who could be already pregnant
- who have any unusual or irregular vaginal bleeding
- who have been treated for breast cancer
- who have heart or liver disease
- who are planning to become pregnant in the near future
- who have had an allergic reaction to the contraceptive injection in the past
The doctor or health care provider will discuss whether the contraceptive injection is the best method for you.
How Is The Contraceptive Injection Used?
The contraceptive injection is given as an injection into the buttock, or sometimes into the muscle of the upper arm. It is usually given during the first five days of the menstrual cycle (the first day of bleeding with your period is day one). When you have the injection during the first five days, it prevents pregnancy straight away.
The contraceptive injection can be given later in the menstrual cycle if there is no chance of an early pregnancy (for example, if there has been no sex since the last period) but it will take another seven days before it is effective. Using condoms or avoiding vaginal sex is advised for the next seven days to prevent an unintended pregnancy.
It is important to keep on having injections every 12 weeks.
The contraceptive injection does not provide protection from sexually transmissible infections (STIs). Condoms can be used at the same time as the contraceptive injection, to help protect against STIs.
Are There Any Side Effects?
All women using the contraceptive injection will have a change to their vaginal bleeding pattern. Bleeding often becomes irregular and can sometimes last longer than before, but heavy bleeding is not very common. Some women have continual light bleeding for some weeks or find that their bleeding stops altogether. Women who use the injection for longer are more likely to have no bleeding at all. Absent bleeding can be normal in women using the contraceptive injection, and is not an indication of any health problems. If you have new or unusual vaginal bleeding, you should discuss this with your doctor.
Some studies have shown that there can be a loss of bone density (bone thinning) with extended use of the contraceptive injection. While the effect on bone density is reversible in most women, women who are already at higher risk for bone loss may be advised to use another method of contraception. The contraceptive injection is not usually recommended as a first-line method for young women under 18 years or women approaching menopause. Women should not use the injection after 50 years of age.
When you stop using the contraceptive injection your periods will take some time to return to their regular cycle. It usually takes about eight months, although it may take more than one year.
Some women may also gain weight, get headaches, experience mood swings or acne while they are using the contraceptive injection.
Getting Pregnant After The Contraceptive Injection
Because it can take some months to return to a normal menstrual cycle after the last injection, it can take even longer to become pregnant.
Women who want to become pregnant in the next 12 to 18 months are advised to use another method of contraception which is more quickly reversible. The number of contraceptive injections does not seem to affect how long it takes to become pregnant.
Women who are stopping the injection but who do not want to become pregnant should use another method of contraception 12 weeks after the last injection.
For More Information
- Contact the Family Planning NSW Talkline 1300 658 886 or go to www.fpnsw.org.au/talkline
- NRS (for deaf) 133 677
- Visit your nearest Family Planning clinic