1. About diclofenac

Diclofenac is a medicine that reduces swelling (inflammation) and pain.

It's used to treat aches and pains, as well as problems with joints, muscles and bones. These include:

Diclofenac comes as tablets and capsules, including slow-release tablets and capsules, and suppositories. These are available on prescription only.

Diclofenac gel and plasters for joint pain are available to buy from pharmacies.

It can also be given as an injection or as eyedrops. These are usually only given in hospital.

A high strength diclofenac gel (containing 3% diclofenac) is used to treat actinic keratoses (dry, scaly patches of skin caused by sun damage). This treatment is usually started after assessment by a dermatologist and is not covered here.

2. Key facts

  • It's best to take the lowest dose of diclofenac for the shortest time to control your symptoms.
  • Take diclofenac tablets or capsules with a meal or snack, or just after eating.
  • Common side effects are stomach pain, feeling or being sick and rashes.
  • Diclofenac gel and plasters can be used twice a day to target pain in a particular area of your body.

3. Who can and cannot take diclofenac

Most adults can take diclofenac.

Children may be prescribed diclofenac to treat joint problems. Diclofenac tablets, capsules and suppositories are suitable for children aged 6 months and above.

Diclofenac gel is suitable for children aged 14 and above. Diclofenac plasters and patches are suitable for young people aged 16 and above.

Diclofenac is not suitable for some people. To make sure it's safe for you, tell your doctor or pharmacist if you:

4. How and when to take or use diclofenac

Always follow the advice of a pharmacist or doctor, and the instructions that come with your medicine.

Diclofenac tablets, capsules and suppositories


You'll usually take diclofenac tablets, capsules or suppositories 2 to 3 times a day.

The usual dose is 75mg to 150mg a day, depending on what your doctor prescribes for you. Follow your doctor's advice on how many tablets to take, and how many times a day.

If your doctor prescribes diclofenac for your child, they'll use your child's weight to work out the right dose for them.

If you have pain all the time, your doctor may recommend slow-release diclofenac tablets or capsules. You'll usually take these either once a day in the evening, or twice a day. If you're taking slow-release diclofenac twice a day, leave a gap of 10 to 12 hours between your doses.

How to take tablets and capsules

Swallow diclofenac tablets or capsules with a drink of milk. If you need to take them with water, take them after a meal or snack. Taking them with milk or food means they'll be less likely to upset or irritate your stomach.

Swallow them whole, do not crush, break or chew them.

How to use suppositories

Suppositories are medicine that you push gently into your anus (bottom).

  1. Go to the toilet beforehand if you need to.
  2. Wash your hands before and after using the medicine. Also clean around your anus with mild soap and water, rinse and pat dry.
  3. Unwrap the suppository.
  4. Gently push the suppository into your anus with the pointed end first. It needs to go in about 3 centimetres (1 inch).
  5. Sit or lie still for about 15 minutes. The suppository will melt inside your anus. This is normal.

Diclofenac gel


You'll usually use the gel 2 to 4 times a day, depending on how strong it is. Check the packaging for more information or speak to your pharmacist.

If you're using the gel twice a day, use it once in the morning and once in the evening. If you're using it 3 or 4 times a day, wait at least 4 hours before putting on any more.

The amount of gel you need depends on the size of the area you want to treat. You'll usually use an amount about the size of a 1 penny or 2 pence piece (2 to 4 grams).

Maximum dose for diclofenac gel

Do not use diclofenac gel more than 4 times in any 24-hour period.

  1. Gently squeeze the tube, or press firmly and evenly on the nozzle of the dispenser, to get a small amount of gel.
  2. Put the gel on the painful or swollen area and slowly rub it in. It may feel cool on your skin. Wash your hands afterwards.

Diclofenac plasters and patches


Treat only 1 painful area at a time. Do not use more than 2 medicated plasters or patches in any 24-hour period.

How to use plasters and patches

  1. Stick a medicated plaster or patch over the painful area twice a day, once in the morning and once in the evening. Take the old patch off before you put the new one on.
  2. Apply gentle pressure with the palm of your hand until it's completely stuck to your skin.
  3. When you want to take the plaster or patch off, it helps to moisten it with some water first. Once you have taken it off, wash the affected skin and rub it gently in circular movements to remove any leftover glue.

What if I forget to take it?

If you forget to take diclofenac, take it as soon as you remember, unless it's nearly time for your next dose. In this case, skip the missed dose and take the next one at the usual time.

Never take a double dose to make up for a forgotten dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember your medicine.

What if I take too much?

Taking more than your prescribed dose of diclofenac tablets, capsules or suppositories can be dangerous. It can cause side effects such as:

  • stomach ache
  • feeling or being sick (vomiting)
  • diarrhoea
  • black poo or blood in your vomit – a sign of bleeding in your stomach
  • headaches
  • drowsiness
  • ringing in your ears (tinnitus)

If you need to go to hospital, take the diclofenac packet or the leaflet inside it, plus any remaining medicine, with you.

Find your nearest A&E

What if I use too many plasters or patches or too much gel?

If you use too many plasters or patches or too much gel by mistake, it's unlikely to do you any harm. But if you use too much and get any side effects, tell your doctor straight away.

5. Taking diclofenac with other painkillers

It's safe to take diclofenac with paracetamol or codeine.

Do not take diclofenac with similar painkillers, like aspirin, ibuprofen or naproxen, without talking to a doctor.

Diclofenac, aspirin, ibuprofen and naproxen all belong to the same group of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). Taking diclofenac together with other NSAIDs may increase your chances of getting side effects like a stomach ache.

NSAIDs are also used in medicines you can buy from pharmacies, such as cough and cold remedies.


Before taking any other medicines together with diclofenac, check the label to see if they contain ibuprofen, aspirin or other NSAIDs.

6. Side effects

Like all medicines, diclofenac can cause side effects, although not everyone gets them.

Common side effects

Common side effects of diclofenac tablets, capsules and suppositories happen in more than 1 in 100 people.

Talk to your doctor or pharmacist if these side effects bother you or do not go away:

  • feeling sick (nausea)
  • being sick (vomiting) or diarrhoea
  • feeling dizzy or vertigo
  • headaches
  • stomach ache, wind or loss of appetite
  • mild rash

You're less likely to have side effects with diclofenac gel or plasters. This is because less medicine gets into your body. But you may still get the same side effects, especially if you use a lot on a large area of skin.

Using diclofenac gel or plasters can affect your skin. It can make your skin:

  • more sensitive to sunlight than normal
  • develop a rash where you applied the gel or plaster
  • dry or irritated (eczema)
  • itchy or inflamed (dermatitis)

Serious side effects

These serious side effects are rare and happen in less than 1 in 1,000 people.

Call your doctor straight away if:

  • you have blood in your vomit or black poo – these could be signs of bleeding in your stomach or gut
  • you have severe indigestion, heartburn or stomach pain, vomiting or diarrhoea – these can be signs of an ulcer or inflammation in your stomach or gut
  • the whites of your eyes or your skin turn yellow, although this may be less obvious on brown or black skin – this can be a sign of liver problems
  • you have a raised, itchy rash, or swollen or puffy skin – these can be signs of hives (urticaria) or oedema (swelling)
  • you have breathlessness, tiredness and swollen legs or ankles – these can be signs of heart failure

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to diclofenac.

These are not all the side effects of diclofenac. For a full list, see the leaflet inside your medicine packet.

7. How to cope with side effects of diclofenac

What to do about:

  • feeling sick (nausea) – take diclofenac with or after a meal or snack. It may also help if you avoid rich or spicy food.
  • being sick (vomiting) or diarrhoea – drink plenty of water or other fluids. If you're being sick, try small frequent sips of water. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Speak to a doctor if being sick or diarrhoea lasts for longer than 3 days. Do not take any other medicines without speaking to a pharmacist or doctor.
  • feeling dizzy or vertigo – if you feel dizzy or unsteady, stop what you're doing and sit or lie down until you feel better. Do not drive or cycle, or use tools or machinery, if you're feeling dizzy or lightheaded. As your body gets used to diclofenac, these side effects should wear off.
  • headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend an alternative painkiller. Headaches should usually go away after the first week of taking diclofenac. Talk to your doctor if they last longer than a week or are severe.
  • stomach ache, wind or loss of appetite – try not to eat foods that cause wind (like peas, lentils, beans and onions). Eat smaller meals, eat and drink slowly, and exercise regularly.
  • a mild rash and dry or irritated, itchy or inflamed skin – use an emollient cream or ointment to moisturise, soothe and hydrate the affected area. If it does not get better within a week or you're worried, speak to a pharmacist or doctor.
  • skin being more sensitive to sunlight – stay out of bright sun and use a high factor sun cream (SPF 15 or above), even on cloudy days. Do not use a sunlamp or sunbeds.

8. Pregnancy and breastfeeding

Diclofenac is not usually recommended in pregnancy.

This is because diclofenac may cause problems for your unborn baby. For example it can affect your baby's circulation and it can cause you to have too little amniotic fluid surrounding your baby in the womb.

Your doctor will only advise you to take diclofenac while you're pregnant if the benefits of taking the medicine clearly outweigh the risks.

There may be other treatments that are safer for you. Paracetamol is generally the best painkiller to take during pregnancy.

Diclofenac and breastfeeding

You can take diclofenac while breastfeeding. Only very small amounts get into breast milk which are unlikely to cause side effects in your baby. Many breastfeeding mothers have used it without any problems.

If you notice that your baby is not feeding as well as usual, or if you have any other concerns about your baby, talk to your midwife, health visitor, pharmacist or doctor as soon as possible.


For more information about how this medicine can affect you and your baby, read this leaflet on diclofenac on the Best Use of Medicines in Pregnancy (BUMPs) website.

10. Cautions with other medicines

There are some medicines that affect the way diclofenac works. Tell your doctor if you're taking:

Mixing diclofenac with herbal remedies or supplements

It's not possible to say that complementary medicines or herbal remedies are safe to take with diclofenac.

They're not tested in the same way as prescription medicines or medicines sold in pharmacies. They're generally not tested for the effect they can have on other medicines.

11. Common questions about diclofenac

Page last reviewed: 10/06/2021
Next review due: 10/06/2024