There are 2 different contraceptive injections available
- Depo-Provera containing medroxyprogesterone acetate 150 mg per 1 ml
- Sayana Press containing medroxyprogesterone acetate 104 mg per 0.65 ml
Depo-Provera is given by a health professional at a clinic while Sayana Press can be self administered at home. For more information about Sayana Press see www.sayanapress.co.uk
The contraceptive injection contains a hormone called progestogen which protects you from pregnancy for 13 weeks.
How effective is it?
The contraceptive injection is very effective with a failure rate of less than 4 pregnancies per 1000 users over 2 years. This means it is over 99.6% effective.
How does it work?
The main way the contraceptive injection works is to stop the ovaries from releasing an egg each month.
How is it given?
It is normally injected into the muscles of your bottom and needs to be given every 12 weeks.
Where can I get the contraceptive injection?
Can anyone use the contraceptive injection?
Most women who want the contraceptive injection can have it.
Conditions which may mean you could not use the contraceptive injection.
- You want to have a baby in the next year
- Now or in the past you have had breast cancer
- You have had a heart attack or a stroke
- You have had certain types of liver disease
- You have had diabetes for a long time or have complications with it
- You have risk factors for osteoporosis (thinning of the bones)
- You have high blood pressure with associated vascular disease
- You have multiple risk factors for cardiovascular disease
- You have unexplained vaginal bleeding
How old do I have to be to start the contraceptive injection?
The contraceptive injection lowers your natural oestrogen levels, which may cause thinning of the bones. In young women, bones are still gaining strength and there are concerns that the contraceptive injection may interfere with this. Your doctor or nurse is likely to encourage you to use other forms of contraception until age 18. However if other methods are not suitable, some young women do choose the contraceptive injection.
What are the advantages of the contraceptive injection?
Some of the good things about the contraceptive injection are:
- Apart from injection visits you do not need to think much about it
- There are no serious side effects
- You can use it if you are breast feeding
- It is useful if you cannot take oestrogens, like those found in the combined oral contraceptive pill
- It may help with pre-menstrual tension and heavy periods
- Sayana Press – can be self administered at home which saves several visits a year
What are the disadvantages of the contraceptive injection?
- Your periods are likely to change. Some women will have irregular bleeding or spotting and for a few the bleeding will last a long time and could be heavy. As time goes on the periods are likely to stop completely.
Problems with bleeding.
If you have problems with bleeding then discuss it with your doctor or nurse. It may be that some tablets would help to control the bleeding. Your doctor or nurse may also wish to check the bleeding is not due to some other causes, such as infection. Even if you do decide to stop the contraceptive injection the bleeding problems could continue for some months.
- Some women may gain weight when they use the contraceptive injection.
- When you start any contraception which contains hormones, you may get some annoying side effects in the first few months. With the contraceptive injection these include spotty skin, sore breasts, headaches, changes in mood and sex drive. These symptoms normally stop within a few months. Speak to your doctor or nurse if you have any concerns.
- If for any reason you decide to stop the contraceptive injection any side effects, including bleeding problems may take a few months to go away
- It may take a while for your periods and fertility to return after stopping the contraceptive injection.
- The contraceptive injection will not protect you from sexually transmitted infections and many women continue to use condoms whilst taking the contraceptive injection.
- The contraceptive injection in some women can reduce the strength of their bones. For most women this is not a problem as the bones get stronger again when you stop the injection. However it may be more of a problem for those women who have risk factors for thin bones (osteoporosis).
Risk factors for osteoporosis
- Periods stopping for 6 months or more because of dieting, an eating disorder or over exercising
- Heavy drinking
- Long term use of steroids
- Close family history of osteoporosis
- Certain medical conditions that affect the liver, thyroid or digestive system
Are there any serious risks linked with using the contraceptive injection?
- As discussed in the section above ‘What are the disadvantages of the contraceptive injection?’ there may be some thinning of your bones.
- There may be a small increase in the risk of breast cancer in women who have used hormonal contraception but the contraceptive injection may give you some protection against cancer of the womb.
- You may have an allergic reaction to the injection or develop an infection at the site of injection but these are both very rare.
Will my weight be affected by the use of the contraceptive injection?
Some though certainly not all women put on weight whilst on the contraceptive injection.
When should I have my first injection of the contraceptive injection?
It is usual to start the contraceptive injection within the first 5 days of your period. This means you will be immediately protected from pregnancy. If it is not possible to start in this way your doctor or nurse will discuss other options with you. If you are given the contraceptive injection after the first 5 days of your period you will not be protected from pregnancy for 7 days after the injection.
When should I have subsequent injections of the contraceptive injection?
You need to have injections every 13 weeks. The doctor or nurse who gives you the injection should tell you when your next injection is due. If you are unable to make this date discuss whether it is possible to come earlier. You can set up an SMS reminder to give yourself the next Sayana Press on www.sayanapress.co.uk. If you do not manage to get the next injection at 13 weeks you need to use alternative contraception such as condoms until your contraceptive injection is given and often you will need to continue to do this for another 7 days after that. If you are overdue for an injection and do have unprotected sexual intercourse you may need emergency contraception such as the ‘morning after pill’. See our section on emergency contraception about this.
Can anything make the contraceptive injection less effective?
- There are no medicines that you can be prescribed or buy in a chemist in the UK which will make the contraceptive injection less effective.
- Diarrhoea and vomiting does not affect the contraceptive injection
How long can I use the contraceptive injection for?
Many women who use the contraceptive injection do so for just a few years but some use it for longer. If you wish to use it for more than 2 years your doctor or nurse will regularly ask you questions to work out whether you are at particular risk of osteoporosis and then together you can decide what would be best for you.
It is important that you are happy with the type of contraception you choose to use. Doctors and nurses are trained to work with you to find a method of contraception that suits you. Do not be afraid to discuss any concerns you may have