What it is?
An injection containing the hormone progestogen.
There two main types of injectable contraceptive:
- Depo-Provera which lasts for 13 weeks
- Sayana Press which lasts for 13 weeks
Depo-Provera is injected into a muscle in your buttocks. Depo-Provera can also sometimes be given in the arm.
Sayana Press is injected beneath the skin at the front of the thigh or abdomen.
How it works
The hormone progestogen stops ovulation (release of an egg) and thickens the mucus around the cervix, making it difficult for sperm to get into the uterus.
It makes the lining of the uterus thinner, so it is less likely to accept a fertilised egg.
Advantages
- Does not interrupt sex
- Women do not have to remember to take a pill
- May protect against cancer of the uterus
- Not affected by other medicines
Disadvantages
- Does not protect against sexually transmitted infections (STIs) so use of condoms also is recommended.
- Periods may be irregular or stop altogether
- Can cause headaches, skin problems, mood changes and breast tenderness
- As the injections last for several weeks, so will the side effects should you experience any- the side-effects can also last for sometime afterwards
- Can take a year or more after stopping the injection for regular periods to return
- Depo-Provera works by lowering levels of the female hormone oestrogen and this can cause slight thinning of the bones by reducing bone mineral density
How effective is it?
Injectable contraception is 99% effective.
What makes it less effective?
- Some prescribed and complementary medicines
- Follow-up injections must be given on time
For more information on different forms of contraception, go to our contraception advice page.
