This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Common side effects of diclofenac
These common side effects of diclofenac tablets, capsules and suppositories happen in more than 1 in 100 people. There are things you can do to help cope with them:
Feeling sick or being sick
Stick to simple meals and do not eat rich or spicy food. It might help to take or use your diclofenac after you've eaten.
If you're being sick, try small frequent sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Diarrhoea
Drink lots of fluids, such as water or squash, to avoid dehydration. Speak to a pharmacist if you have signs of dehydration such as peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
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.
Talk to your doctor if headaches do not go away or are severe.
Stomach ache
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 are in a lot of pain, speak to your pharmacist or doctor.
Wind (farting)
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.
Loss of appetite
Eat when you would usually expect to be hungry. If it helps, eat smaller meals more often than usual. Snack when you're hungry. Have nutritious snacks that are high in calories and protein, such as dried fruit and nuts.
Mild rash
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.
View the original NHS website page ↗. Refreshed 19 August 2026.
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