The Contraceptive Injection
Currently used as the contraceptive method of choice for 3% of women aged 16 to 49, the contraceptive injection is becoming increasingly popular. A progestogen-only injection, it administers progestogen to the body in order to prevent pregnancy. There are two types of contraceptive injections available in the UK:
- Depo-Provera is the most commonly used progestogen-only injection. It lasts for 12 weeks
- Noristerat (norethisterone) lasts for eight weeks
How does it work?
The contraceptive injection works in three ways to effectively reduce the risk of pregnancy. Administered by injection into the muscle, the hormones work by firstly stopping ovulation by preventing the release of an egg from the ovaries. Secondly, they thicken the mucus produced in the cervix to make it harder for the sperm to reach the womb. Thirdly, the lining of the womb is made thinner, so that even if an egg were produced and then fertilised, it would not be able to attach itself to the womb wall.
What are the benefits?
The biggest benefit of this method is its long-term effectiveness as a contraceptive. Once you’ve received the injection, you don’t need to do anything else and you’ll be protected for as long as the injection lasts. It is also worth considering that:
- This method is more than 99% effective
- You do not need to remember to take a pill or secure a new patch
- It is not affected by other medications
- Studies have shown that it can offer some protection against cancer of the womb, ectopic pregnancy and ovarian cysts
- Although it may take a while, it is reversible which means your fertility will return
Are there any side effects?
Like all hormonal contraceptives, there is a risk of side effects with the contraception injection. These generally include; prolonged, heavy or irregular periods, headaches, mood swings, breast tenderness, bloating, weight gain and a delay in the return of fertility once the treatment is stopped.
Although this treatment is effective in preventing pregnancy, you should not use this treatment if you have a history of thrombosis, liver or heart disease or circulatory problems, experience migraines with aura, have had diabetes for over 20 years, suffer from osteoporosis, think you might be pregnant or are planning to have children over the next year.