The contraceptive depot injection (also called the Depo-Provera injection) is an effective, long-acting hormonal contraceptive that contains progestogen. It is given as an injection and provides protection from pregnancy for 12–13 weeks, depending on the type used.
How does the injection work?
The injection prevents pregnancy by:
- Stopping ovulation (no egg is released)
- Thickening cervical mucus to block sperm
- Thinning the lining of the womb to reduce the chance of implantation
How effective is it?
- Over 99% effective when injections are given on time
- One of the most reliable forms of contraception available
How is the injection given?
- The injection is given into a muscle in your upper arm or buttock by a trained nurse or doctor
- The procedure is quick, usually taking only a few minutes
No special preparation is needed
When does it start working?
- If given within the first 5 days of your period → protected immediately
- If given at any other time → use additional contraception for 7 days
Advantages of the depot injection
- Long-acting: works for 12–13 weeks per injection
- Highly effective and reversible
- No daily pills or weekly patches to remember
- Suitable for people who cannot take oestrogen
- Can be used while breastfeeding
Possible side effects
Some people may notice:
- Changes in bleeding patterns (irregular, lighter, or no periods)
- Weight gain
- Breast tenderness
- Headaches or mood changes
- Temporary delay in fertility after stopping
Most side effects improve over time, but your healthcare professional can discuss options if they persist.
Important safety information
The injection is not suitable for everyone, especially if you have:
- Severe liver disease
- Breast cancer
Other health conditions may require discussion with your GP before starting the injection.
Follow-up and repeat injections
- Injections must be given every 12–13 weeks to remain effective
- Book your next appointment in advance to ensure continuous protection
- Fertility may take a few months to return after the last injection
Our services
We provide:
- Contraceptive injection appointments and reviews
- Advice on side effects
- Support for switching methods
All consultations are confidential.
When to seek urgent advice
Contact us if you experience:
- Severe abdominal pain or unexplained bleeding
- Signs of infection at the injection site
Any other concerning symptoms