Two of the most widely used pain relievers on earth, sold over the counter in nearly every country, yet they work through completely different pathways and carry very different risks. The ibuprofen vs paracetamol question is essentially the same as “ibuprofen vs acetaminophen” for American readers, because paracetamol is the international name for the drug the US labels acetaminophen. Ibuprofen is an NSAID; paracetamol is a central-acting analgesic and antipyretic. Our medical conditions guide offers broader context. The short answer: ibuprofen is stronger for inflammation, paracetamol is gentler on the stomach and kidneys, and both are considered first-line OTC options for mild to moderate pain.
Ibuprofen and Paracetamol: Quick Comparison
Paracetamol (acetaminophen) is available OTC as 500 mg and 1,000 mg tablets in most countries, with a daily ceiling of roughly 3,000 to 4,000 mg. Ibuprofen OTC is 200 mg (400 mg in some countries), with a daily ceiling of 1,200 mg. The FDA classifies acetaminophen as an analgesic and antipyretic; ibuprofen is classified as an NSAID.
How Each One Works
Ibuprofen inhibits cyclooxygenase enzymes (COX-1 and COX-2), reducing prostaglandin synthesis throughout the body. This peripheral action reduces pain, fever, and inflammation at the injury or infection site.
Paracetamol works primarily in the central nervous system. Cleveland Clinic notes that it raises pain thresholds through brain and spinal cord pathways while doing little for peripheral inflammation. That is why ibuprofen shrinks a swollen ankle but paracetamol does not.
Effectiveness: Head-to-Head Research
A Cochrane review of post-operative pain found ibuprofen 400 mg outperformed paracetamol 1,000 mg for dental extraction pain, with a lower number-needed-to-treat. Combining the two beat either alone.
For fever, both reduce temperature by roughly the same amount, though ibuprofen’s effect may last slightly longer in children per AAFP reviews. For tension headaches, studies generally favor ibuprofen 400 mg slightly over paracetamol 1,000 mg.
Side Effects Compared
Paracetamol’s main risk is liver toxicity at doses above 4,000 mg per day, or lower in heavy drinkers and those with liver disease. Short-term use at recommended doses is very well tolerated. NIH data identify paracetamol overdose as the leading cause of acute liver failure in the US.
Ibuprofen’s risks include stomach irritation, ulcers, GI bleeding, kidney strain, elevated blood pressure, and cardiovascular events. Taking with food reduces stomach upset. People with ulcers, heart failure, or chronic kidney disease should avoid ibuprofen without medical clearance.
Dosing and How to Take Each
Adult paracetamol: 500 to 1,000 mg every 4 to 6 hours, max 3,000 to 4,000 mg per day from all sources. Adult ibuprofen: 200 to 400 mg every 4 to 6 hours, max 1,200 mg per day OTC. Ibuprofen should be taken with food or milk; paracetamol can be taken with or without food. See our ibuprofen dosing guide for more detail.
Which Is Better for Pain, Fever, and Inflammation?
For sprains, strains, arthritis, menstrual cramps, dental pain, and any condition where swelling is part of the pain picture, ibuprofen is stronger. For tension headaches, post-vaccine soreness, general aches, and fever in healthy people, paracetamol is often enough and is gentler on the stomach.
In pregnancy, paracetamol is generally the preferred first-line option because ibuprofen is contraindicated in the third trimester. For a three-way comparison, see our naproxen vs ibuprofen vs acetaminophen article.
Cost and Availability
Both are inexpensive generics available OTC worldwide. In the US, generic ibuprofen 200 mg runs about $5 to $10 per 100 tablets, and generic acetaminophen (paracetamol) 500 mg runs $4 to $8 per 100 tablets. In the UK and Europe, paracetamol is often sold at near-cost to discourage bulk purchase and reduce overdose risk.
Drug Interactions and Warnings
Paracetamol interacts with warfarin (can elevate INR) and alcohol. Combination cold medicines often contain hidden paracetamol, which is a common source of accidental overdose. Ibuprofen interacts with blood thinners, SSRIs, lithium, methotrexate, ACE inhibitors, and low-dose aspirin. Our acetaminophen vs paracetamol article explains why they are the same drug.
When to seek emergency care: Call Poison Control (1-800-222-1222) or go to the ER immediately if you have taken more than the recommended dose of either medication.
Frequently Asked Questions
Can you take ibuprofen and paracetamol together?
Yes. They work through different pathways and clear through different organs (ibuprofen through kidneys, paracetamol through liver). Combining them is a common strategy for moderate pain.
Which is safer for children?
Both are considered safe at weight-based doses for age-appropriate children. Paracetamol is used from birth under physician guidance; ibuprofen is approved from 6 months old. Avoid aspirin in anyone under 18.
Which is better during pregnancy?
Paracetamol is generally the preferred first-line choice during pregnancy because ibuprofen is contraindicated in the third trimester. Always confirm with an OB provider.
Which works faster?
Both reach peak effect in 30 to 60 minutes. Liquid and dissolvable formulations may absorb slightly faster, but the clinical difference is minor.
Bottom Line
Ibuprofen is stronger for inflammation-driven pain; paracetamol is gentler on the stomach and safer in pregnancy. Both are effective for mild to moderate pain and fever. If you have no contraindications, pick ibuprofen for injuries and menstrual cramps, and paracetamol for tension headaches and general soreness. For stubborn pain, combining them is supported by randomized evidence.