Paracetamol and ibuprofen are the two most widely purchased medicines in the UK — yet the important differences between them are poorly understood by most people. Using the right one for the right situation improves effectiveness, reduces side effects, and avoids potentially dangerous errors.
How They Work Differently
Paracetamol (acetaminophen) — mechanism is not fully understood despite decades of use. It acts centrally in the brain and spinal cord to raise the pain threshold and reduce fever. Crucially, it has minimal anti-inflammatory action — it is an analgesic and antipyretic, not an anti-inflammatory. Ibuprofen — a non-steroidal anti-inflammatory drug (NSAID). Inhibits COX-1 and COX-2 enzymes, reducing prostaglandin synthesis. Prostaglandins mediate pain sensitisation, inflammation, and fever — so ibuprofen addresses all three: pain, inflammation, and fever. The inflammatory mechanism makes ibuprofen specifically more effective than paracetamol when inflammation is a driver of the pain.
When Paracetamol Is the Better Choice
Headaches and tension headaches — typically non-inflammatory; paracetamol is first-line. Fever — both reduce fever equally; paracetamol is preferable when ibuprofen is contraindicated. Pain in those with GI sensitivity — paracetamol doesn’t irritate the stomach. Pain in those taking anticoagulants — ibuprofen increases bleeding risk; paracetamol at correct doses is safe with warfarin and DOACs. Pain in pregnancy — paracetamol is the only OTC analgesic recommended in pregnancy. Pain in people with kidney or cardiovascular disease — ibuprofen causes renal vasoconstriction and fluid retention; paracetamol is significantly safer. Children from 2 months — paracetamol is licensed from 2 months.
When Ibuprofen Is the Better Choice
Musculoskeletal pain — back pain, sprains, strains, arthritis — inflammation is a key component; ibuprofen is significantly more effective than paracetamol for these. Period pain (dysmenorrhoea) — prostaglandins cause uterine cramping; ibuprofen directly reduces prostaglandin production and is more effective than paracetamol for this indication. Dental pain — significant inflammatory component; ibuprofen is preferred. Sore throat with inflammation — ibuprofen reduces inflammatory pain more effectively. Post-surgical pain (mild-moderate, with no contraindications).
Contraindications and Cautions
Avoid ibuprofen in: active or history of peptic ulcer disease; significant renal impairment; heart failure; known cardiovascular disease (high dose, long-term); pregnancy (especially from 20 weeks onwards); aspirin-sensitive asthma (~10% of asthmatics); children under 3 months. Paracetamol overdose is the most common cause of acute liver failure in the UK — staggered overdose (repeatedly exceeding the recommended dose over days) is particularly dangerous because symptoms are delayed. Maximum dose: 4g (8 x 500mg tablets) in 24 hours for a healthy adult; 3g for those who drink regularly, are malnourished, or have liver disease.
Frequently Asked Questions
Can I take paracetamol and ibuprofen together?
Yes — they have completely different mechanisms and different metabolism pathways; there is no pharmacological interaction. They can be taken simultaneously or alternated. The combination provides additive pain relief and is supported by clinical evidence for moderate pain. This is why many combination pharmacy products exist.
Is ibuprofen safe for regular use?
Short-term use at recommended doses is safe for most healthy adults. Regular long-term use significantly increases the risks of GI bleeding (particularly without food), renal impairment, and cardiovascular events. Anyone taking ibuprofen regularly (more than 10 days per month) should discuss this with their GP or pharmacist and consider a proton pump inhibitor for gastroprotection.
Browse pain relief products at Huncoat Pharmacy. Related: Back Pain, Migraine, Period Pain.
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