Contraceptive injection
What is it? An injection of the hormone progesterone which provides a longer acting alternative to the contraceptive pill (each injection lasts for 12 weeks). It works by slowly releasing the hormone progestogen into the body to stop ovulation and thickens cervical mucus which prevents sperm from reaching an egg. It also thins the lining of the womb to prevent an egg implanting.
Advantages:
- Don’t have to remember to take a pill every day
- May make periods lighter and less painful
- Not affected by any other medicines
- Does not interfere with the spontaneity of sex
- May offer some protection against cancer of the uterus
Considerations:
- May make periods irregular
- May take up to a year for fertility to return to its normal level
- Need to remember to attend appointments every 12 weeks for a further injection
- Possible side effects include weight gain, headaches, mood changes and breast tenderness. Side effects will continue for as long as the injection lasts
- Does not protect against sexually transmitted infections
Available from: Available from your GP, local family planning clinic or specialist clinic such as Marie Stopes Reproductive Choices
Effectiveness: Over 99% effective