How safe is your favourite painkiller?
Most of us don’t think twice before popping a few over-the-counter painkillers, but does new research question their safety?
Most of us don’t think twice before popping a few over-the-counter painkillers, but does new research question their safety?
Over-the-counter painkillers like ibuprofen and paracetamol can help us manage minor health niggles without needing to go to the doctor. Cheap and easy to get hold of from the pharmacy, supermarket or corner shop, they're consumed in vast quantities.
Some 6,300 tonnes of paracetamol are sold every year in the UK, for example. That’s roughly 70 tablets, pills or capsules per person, every single year.
But after five decades of widespread use – during which time scientists have learned a lot, both about how they work and their potential side effects – a growing number of experts are asking if these everyday medicines are as safe as we once assumed?
Let’s look at the latest on what we know about paracetamol, ibuprofen – and aspirin (which is no longer recommended as a painkiller).
Paracetamol is the most widely used over-the-counter product in the world for pain and fever.
Astonishingly, scientists still don’t know exactly how it works. It’s thought to block prostaglandins – chemical messengers involved in inflammation that can ramp up the perception of pain in the body and the brain.
“This would be my pick for short-term pain – headaches, that horrible achiness from a bad cold or flu, mild joint pain, and after an accident or minor surgery,” says Fiona McIntyre of the Royal Pharmaceutical Society Scotland.
Most of us are aware that a paracetamol overdose can damage the liver – sometimes fatally. What is less well-known is its potential for harmful side effects, especially in older people.
A major study of the health data of over-65s by the University of Nottingham, published in November 2024, found that prolonged regular use was associated with the risk of stomach ulcers, bleeding, high blood pressure, heart failure and kidney disease, though it’s worth noting that this was in people prescribed paracetamol rather than those who bought it over the counter.
Paracetamol’s perceived mantle of safety has led to it being recommended as the go-to drug for osteoarthritis (OA). However, Professor Weiya Zhang, who led the aforementioned study, says: “Given its minimal pain-relief effect, [its use] as a first-line painkiller for long-term conditions such as osteoarthritis in older people needs to be carefully considered.”
Not really, concluded a 2019 review by Philip Conaghan, professor of musculoskeletal medicine at the University of Leeds, and honorary consultant rheumatologist for Leeds Teaching Hospitals NHS Trust. He concluded that paracetamol's effect on joint stiffness, pain and function was often too small to be clinically significant, and, in some cases, impossible to distinguish from placebo.
The latest NICE guidance on osteoarthritis recommends paracetamol be used “infrequently for short-term pain relief only when other pharmacological treatments are contraindicated, not tolerated or ineffective”.
There is also very little evidence that it works for lower back pain, observes Professor David Webb at the University of Edinburgh: “If you have prolonged lower back pain, see your GP, who can refer you to a specialist if needed.”
One 2022 trial of 103 people with high blood pressure (the PATH-BP trial) found that paracetamol use pushes up blood pressure readings by about 5 millimetres of mercury in long-term users.
“It may not sound much, but it gives something like a 20% or so increased risk of heart attack or stroke,” says Professor Webb, who co-led the trial at the University of Edinburgh.
A former president of the British Pharmacological Society (BPS), he has special interests in the management of high blood pressure, chronic kidney disease and cardiovascular risk management.
The main culprit is a rise in systolic blood pressure (the top figure of your blood pressure reading that measures the pressure in your arteries when the heart beats). And while the rise did vary between individuals, Professor Webb urges: “If you’re taking paracetamol long-term, make sure you see your doctor for regular blood pressure checks.”
No more than eight 500mg tablets a day, or four 1g tablets if prescribed by a doctor, with at least four hours between doses.
While the odd one or two extra tablets is unlikely to do you any harm, if you take too much paracetamol – even if you feel well – go to 111.nhs.uk or call 111.
Paracetamol can interact with medications such as warfarin, and increase the risk of bleeding, especially if taken regularly.
“If you’ve been taking it daily for more than three to six months, try a break or cut down your dose to see if it’s still effective,” suggests Dr Emma Davies, principal pharmacist for pain, analgesic stewardship and harm reduction at the Cwm Taf Morgannwg University Health Board. Dr Davies is co-founder of Live Well with Pain and a member of the British Pain Society.
Be careful if you’re taking cold and flu remedies, as they often contain paracetamol and you could unwittingly take too much. “Read the label and check with your pharmacist before taking other meds on top of paracetamol and risking an accidental overdose,” advises McIntyre.
Dr Davies adds, “If you have liver disease, or you like a tipple (more than 14 units a week), or you weigh less than 50kg (7st 12lbs), check with your doctor or pharmacist before taking paracetamol.”
A non-steroidal anti-inflammatory drug (NSAID), ibuprofen blocks chemicals that cause pain, swelling and inflammation. “Reducing inflammation helps ease pain and lets you move more, which helps reduce pain further,” says Dr Davies.
“Ibuprofen is a good choice for headaches, joint and muscle pain, toothache and any inflammatory pain, such as back pain or after injury,” says McIntyre.
While occasional use shouldn’t cause any problems, a large international study published in 2013 found that high doses increase the risk of major heart and circulatory problems – such as heart attack, stroke or dying from cardiovascular disease – by around a third.
The study’s authors pointed out that the risks were mainly to people who needed to take high doses over a prolonged period, such as those with arthritis – not those who took a short course of lower-dose tablets for something temporary like a muscle sprain.
Research published in July 2025 concluded that the risk of cardiovascular problems from ibuprofen are lower than for other NSAIDs. However, McIntyre advises: “If you are needing to take ibuprofen regularly or in large amounts, seek medical advice.”
Yes, in general, say our experts. “Ibuprofen can irritate the stomach, so it’s important to take with or after food,” says Dr Davies.
It’s not suitable for you to take at all if you have reflux, a history of ulcers, or gastrointestinal bleeding – unless you protect your stomach by taking a medication such as a proton pump inhibitor (PPI), prescribed by your doctor.
If you take blood-pressure medication, steroids, diuretics or SSRIs (antidepressants), ibuprofen may increase the risk of side effects or kidney problems. “It can also worsen asthma or symptoms of heart failure in some people,” McIntyre adds.
Long-term or excessive use can also lead to kidney damage in older people, “especially if you’re unwell in hot weather, or not eating or drinking properly,” she says. Watch out for symptoms like nausea, dizziness and stomach pain – and always go for the lowest effective dose for the shortest time.
Paracetamol wins the day, despite the recent research questioning its safety profile. Professor Webb suggests starting with paracetamol, and if that doesn't work, move on to ibuprofen. All of our experts agree that you should use painkillers for the shortest time you need them, at the lowest does that works.
What about long-term use? “Chronic pain (pain lasting more than three months) always starts as an acute pain before setting in, so I’d advise sticking with paracetamol if it works, as it usually has fewer side effects, says Dr Davies. "You can then switch to an NSAID if paracetamol doesn’t provide enough relief.
“If a combination of paracetamol and an NSAID is needed, and the pain isn't controlled or you aren't sure where it's coming from, it's time to seek expert help.”
Many of us grew up with aspirin as the go-to painkiller – the thing our parents reached for if we complained about a minor ache or pain. So it may come as a surprise that it’s rarely recommended for pain nowadays. The reason? In the dose needed for pain relief, it can cause gastrointestinal bleeding.
Aspirin irreversibly blocks COX, the enzyme involved in inflammation, and the way platelets – the cells that make blood clot – work. Most cells can remake COX after aspirin blocks it, but platelets can’t because they don’t have the machinery to rebuild it, explains Professor Webb.
“While big doses of aspirin are good at reducing inflammation and managing pain, the drug comes with more side effects than paracetamol or the newer NSAIDs, so we just don’t use it for that purpose any more,” he explains.
“Low-dose aspirin (mini aspirin, 75mg) may be recommended for what we call secondary prevention after a heart attack or stroke,” says Dr Davies. “For most older adults who haven’t had a heart attack or stroke, the bleeding risks outweigh the benefits.”
Steer clear, too, if you’re already taking another NSAID, or a blood thinner such as warfarin or apixaban, or if you have gastrointestinal issues such as reflux or ulcers.
The bottom line? Unless you've been prescribed aspirin for other purposes, this is one to remove from your arsenal of analgesics, as it’s no longer recommended for pain.
Yes, but there are rules:
Effervescent tablets might seem appealing because they dissolve quickly and are said to act faster, but those bubbles can come at a cost. “You need to know what’s making them effervescent – and most of it is produced by sodium, which raises blood pressure,” says Professor Webb.
“I don’t think the absorption is much improved, but the salt load is increased. Half of people over-65 will have high blood pressure, whether treated or not, so it’s best to steer clear.” He adds: “If you can’t swallow tablets, there are safer alternatives such as liquid preparations used for children.”
“These usually contain caffeine, which gives you a bit of a buzz but doesn't really offer any advantage in terms of dealing with pain any faster,” says Professor Webb.
For most people, yes. “However, some find that certain formulations are better tolerated, possibly due to other ingredients rather than the drug itself,” says Dr Davies.
Health insurance for people over 50 that provides a quicker route to diagnosis and planned medical treatment in a private facility.
Underwritten by Bupa Insurance Limited.
We partner with Co-op Legal Services to offer advice and services for you and your family.
Are you retiring at the wrong age? The best age to retire for your body, brain, happiness and pocket.
Everything you need to know about the lung infection, and how you could be ill with “walking” pneumonia without realising it.
Strong calves for a strong mind: how they support our circulation and brain health, with easy moves to strengthen yours at home.
Our GP Dr Mark Porter explains what can cause itchy skin, which is a common problem as we get older.
Worried you’ve morphed into Victor Meldrew? Find out how to battle that bad mood, and what to do if you’re stuck with a grouchy loved one.
The benefits of heat and cold therapy, and how Nordic bathing won over our nervous writer.
Here’s how to spot the symptoms of heat disease and reduce your danger.
The NHS winter vaccination campaign kicks off next week. Here’s the lowdown on what you need to book.
Pilates for back pain – what to do if you are suffering, and five gentle exercises that could help.
Dizziness or vertigo: a sensation of spinning, can stop us doing everyday things for fear of falling. Try these tips to stop feeling dizzy
You don’t have to put up with bladder leaks. We try out the latest pelvic floor gadgets for men and women.
Cataracts are a normal part of ageing. Learn how to spot the signs – and when it’s time to consider surgery.
