Like all medicines, medroxyprogesterone contraceptive injections can cause side effects although not everyone gets them.
Common side effects
These common side effects of medroxyprogesterone contraceptive injections happen in more than 1 in 100 people. There are things you can do to help cope with them:
Headaches
Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller.
Talk to your doctor if headaches last longer than a week or are severe.
Stomach pain
Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help. If you're in a lot of pain, speak to your pharmacist or doctor.
Feeling bloated
Try not to eat foods that cause wind (like lentils, peas, beans and onions). Eat smaller meals, eat and drink slowly, and exercise regularly. There are pharmacy medicines that can also help, such as charcoal tablets or simeticone. Speak to a pharmacist for advice.
Feeling sick (nausea)
It may help if you avoid rich or spicy food.
If it does not go away or it's severe, tell your doctor. They may be able to prescribe an extra medicine to help with this side effect.
Feeling nervous or depressed
Talk to your doctor if you have problems with mood changes and it does not improve.
Changes to your periods
Talk to your doctor if you have irregular bleeding, or bleeding after you have not had a period for a while. They may be able to prescribe medicine to help, or arrange for extra tests if you need them.
Weight gain or weight loss
You may lose weight when having medroxyprogesterone injections, but it's more common to gain weight. This is often a small amount.
Eating a healthy, balanced diet and regular exercise will help you keep to a healthy weight.
Lower sex drive
Speak to your doctor if you have problems with your sex drive (loss of libido). You may need to consider using a different contraceptive.
Feeling dizzy
Stop what you're doing and sit or lie down until you feel better. Do not drive, cycle or use tools or machinery if you're feeling dizzy.
Breast tenderness
Try to wear a well-fitting and comfortable bra.
Back pain
Try taking a painkiller, such as paracetamol or ibuprofen.
Feeling tired or weak
Try to get plenty of rest. Do not drive, cycle or use tools or machinery if you're feeling tired. Do not drink alcohol as it will make you feel worse.
Itchy skin
It may help to take an antihistamine which you can buy from a pharmacy. Check with the pharmacist to see what type is suitable for you.
Acne
Wash with a mild soap or cleanser and lukewarm water. Avoid using too much make-up and cosmetics. Speak to a pharmacist for advice about treating acne.
Hair loss
Thinning hair or mild hair loss can be stressful but it is not usually a sign of anything to worry about. Talk to your pharmacist or doctor if you're concerned. Some hair loss treatments are available.
Fluid retention such as swollen ankles
Raise your legs when you're sitting down. Try not to stand for a long time.
If it does not improve or you're also short of breath, talk to your doctor.
Changes to vaginal discharge
Changes including an increase in vaginal discharge are common and are not usually anything to worry about. Talk to your doctor if your discharge changes in smell, colour or texture, as it might be a sign of an infection.
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Serious side effects
Serious side effects are rare and happen in less than 1 in 1,000 people.
Call your doctor or call 111 now if:
- you have a high temperature or feel cold and shivery, get a burning feeling when peeing, have pain in your back or side, or blood in your pee – these can be signs of a urinary tract infection (UTI)
- you get pain, swelling, redness and warmth in a leg or arm – this could be a sign of deep vein thrombosis (DVT)
- you get a red painful lump or swelling where you had the injection – this could be a sign of an injection site abscess or infection and it will need to be treated straight away before the infection gets worse
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin, or if you have pale poo and dark pee – these can be signs of liver problems
- you get blurred vision or double vision – this could be a sign of a build-up of fluid in your eye (oedema)
Immediate action required: Call 999 or go to A&E if:
- you're suddenly short of breath or get a sharp pain in your chest and a cough, or you're coughing up blood – these may be signs of a blood clot in your lungs
- you lose vision suddenly in one or both eyes – this could be a sign of a blood clot
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to a medroxyprogesterone contraceptive injection.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Long-term side effects
If you have medroxyprogesterone contraceptive injections for a long time, your bones may become weaker or more fragile (osteoporosis).
To help prevent this, try exercising regularly, and make sure you get enough calcium in your diet to help strengthen your bones. Milk, cheese and leafy greens contain lots of calcium.
Other side effects
These are not all the side effects of medroxyprogesterone contraceptive injections. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.