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Which painkiller?

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Healthily's medical team
Last reviewed: 20/11/2020
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There are many different painkillers and the type of pain they work best on isn’t always the same.

For pain that’s caused, at least in part, by inflammation, such as back pain, anti-inflammatory painkillers work best.

But for pain that’s caused by sensitive or damaged nerves, such as shingles or sciatica, painkillers that work on the nervous system are a better option.

While painkillers have an obvious benefit (they help get rid of your pain) they also have potential side effects. This means you shouldn’t take them unless you need them and you’re confident that they’re safe for you.

A doctor or pharmacist is the best person to ask about the right painkiller for your pain and how to take it safely. As a starting point, here’s a quick guide to 6 different types of painkillers you may have heard of.


Paracetamol is a simple painkiller that’s used to treat headaches and most pain not caused by your nerves.

Up to two 500mg tablets of paracetamol every 4 to 6 hours is thought to be a safe dose for adults, but make sure you don’t take more than eight 500mg tablets in a day.

Paracetamol doesn't usually cause side effects, but it can cause liver and kidney damage if you take more than the recommended dose. Don’t be tempted to increase the dose if your pain is really bad – see a doctor instead.

You should also see a doctor if your pain lasts for more than 3 days.

Read more about paracetamol.

Ibuprofen and other NSAIDs

Ibuprofen is a type of anti-inflammatory painkiller known as a non-steroidal anti-inflammatory drug (NSAID). Diclofenac and naproxen are other examples of NSAIDs you may have heard of. This group of painkillers tends to work better on pain that’s caused by some sort of inflammation, such as back pain, arthritis or an injury.

But NSAIDs aren’t safe for everyone.

Speak to a doctor before taking an anti-inflammatory painkiller if you:

  • have heart or kidney disease
  • have a stomach condition, including ulcers and indigestion
  • have asthma
  • are pregnant
  • are 65 or older

NSAIDs can cause serious side effects, like bleeding in the stomach, kidney damage and heart problems, so don't take more than the recommended dose, and don’t take them for days or weeks on end.

If you want to use NSAIDs to manage any pain you’re in, speak to a doctor or pharmacist about how much you should take and for how long.

Read more about ibuprofen.


Aspirin is another type of NSAID. It helps with the signs and symptoms of inflammation, but it’s not as effective at relieving pain as other NSAIDs, so it’s not usually used to treat pain.

What aspirin is really good for is bringing down a high temperature and preventing blood from clotting. That’s why it’s more commonly used to treat fevers and to reduce the likelihood of a stroke in people at increased risk.

It’s also good for managing migraine symptoms if you take it as soon as you notice them.

Aspirin has been linked to an increased risk of a condition called Reye’s syndrome in under 16s, so don’t give it to children.

Aspirin can also be unsafe for some adults. Speak to a doctor before taking it if you:

  • have asthma and growths in your nose (nasal polyps)
  • have ever had a stomach ulcer
  • have a bleeding disorder
  • have liver or kidney disease
  • have heart failure or another type of heart disease
  • are pregnant or breastfeeding
  • have anaemia, gout or high blood pressure
  • have an overactive thyroid, lupus or another connective tissue disease
  • are 65 or older
  • are taking blood-thinning medication

Read more about aspirin.


Codeine is a type of painkiller known as an opiate. It isn’t very good at treating pain when you take it on its own, but it works much better when it is taken with paracetamol in a single pill, known as co-codamol (paracetamol and low-dose codeine).

It’s possible to become dependent on codeine – taken on its own or in co-codamol – so it’s important to get advice from a pharmacist or doctor before you start taking it.

Codeine can be unsafe for some people, including those with:

  • COPD, asthma (especially during an asthma attack) or other lung conditions
  • a brain tumour, abscess, head injury or other type of brain condition that can raise the pressure in your skull
  • liver disease
  • certain gut conditions, like ulcerative colitis

You should also avoid taking codeine if you’re breastfeeding, trying to get pregnant or drink a lot of alcohol (more than the amount recommended in your country). Speak to a doctor first.

Codeine and co-codamol can cause side-effects, such as constipation, feeling sick and/or sleepy, and headaches.

Amitriptyline and gabapentin

Amitriptyline is a medicine that was originally used to treat depression and gabapentin is used to treat epilepsy.

But both are also good at treating nerve pain, such as shingles, sciatica and nerve pain caused by diabetes.

And amitriptyline can also prevent migraines and ongoing tension headaches.

Amitriptyline and gabapentin should be taken regularly to help with nerve pain, but bear in mind that both have side-effects, including feeling sleepy and dizziness. It’s also possible to become dependent on gabapentin, so speak to a doctor before taking it.

Gabapentin and amitriptyline are not recommended if you’re pregnant unless your doctor feels that the benefits clearly outweigh the risks. There’s evidence that amitriptyline may cause harm to the baby and with gabapentin there is not enough information to say that it is safe. If you are planning to become pregnant or find out that you are pregnant whilst taking this medication/these medications, speak to your doctor and midwife as soon as possible.


Morphine and morphine-like medicines, such as oxycodone, fentanyl and buprenorphine, are the strongest of all painkillers, so they’re only used to treat severe pain that other painkillers can’t relieve.

They come as tablets, injections, patches and drinks. It’s possible to become dependent on any of them, so only take morphine if a doctor or pain specialist is monitoring you.

Morphine and morphine-like medicines can cause side-effects like constipation and feeling sleepy and/or sick. They can also be unsafe for some people, including those with:

  • head injuries
  • alcohol dependency
  • low thyroid hormone levels
  • breathing problems
  • conditions that causes fits and seizures

So, which painkiller is best for my pain?

As these 6 painkillers show, different painkillers work best for different types of pain. This means that before choosing a painkiller, you should consider the type of pain it treats, the side-effects it can cause and whether you have any health conditions that make it unsafe to take the painkiller.

Painkillers can cause serious side-effects, so speak to a pharmacist or doctor for advice before taking them. And take care to also read the information leaflet provided with the painkiller.

Key points

  • many different types of painkillers exist, but they treat different types of pain
  • paracetamol is a simple painkiller used to treat headaches and most non-nerve pains
  • aspirin isn’t very good at treating pain, but can help with fever and migraine symptoms
  • NSAIDs, like ibuprofen, are best for pain caused by inflammation
  • codeine works better when combined with paracetamol (co-codamol)
  • amitriptyline and gabapentin are medicines used to treat nerve pain
  • morphine and morphine-like painkillers should only be used for severe pain and you should be monitored by a doctor or pain specialist while taking it

Additional references

  1. Analgesia - mild-to-moderate pain | NICE [Internet]. Cks.nice.org.uk. [cited 9 November 2020]. Available here.
  2. Which painkiller? | NHS [Internet]. nhs.uk.. [cited 9 November 2020]. Available here.
  3. Aspirin | NICE Excellence [Internet]. Bnf.nice.org.uk. [cited 9 November 2020]. Available here.
  4. Co-codamol for adults: painkiller containing paracetamol and codeine | NHS [Internet]. nhs.uk. [cited 9 November 2020]. Available here.
  5. Co-codamol for adults: painkiller containing paracetamol and codeine | NHS [Internet]. nhs.uk. [cited 9 November 2020]. Available here.
  6. Amitriptyline: a medicine used to treat pain and prevent migraine | NHS [Internet]. nhs.uk. [cited 9 November 2020]. Available here.
  7. Gabapentin | NICE Excellence [Internet] Bnf.nice.org.uk. [cited 9 November 2020]. Available here.
  8. Amitriptyline Hydrochloride | NICE Excellence [Internet}. Bnf.nice.org.uk. [cited 9 November 2020]. Available here.
  9. Morphine: strong painkiller to treat severe pain | NHS [Internet]. nhs.uk. [cited 9 November 2020]. Available here.
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