Ibuprofen vs Paracetamol: What’s the Difference and When to Use Each
Ibuprofen and paracetamol are Britain’s most widely used over-the-counter medicines — yet many people aren’t sure which to reach for, or assume they work the same way. They don’t. Understanding the difference can make your pain relief significantly more effective.
How Paracetamol Works
Paracetamol (acetaminophen) acts primarily on the central nervous system, raising the pain threshold and reducing fever by acting on the hypothalamus. Crucially, paracetamol does NOT reduce inflammation. It’s what’s called a “pure analgesic and antipyretic.” This means it will reduce the sensation of pain and bring down a temperature, but if your pain is being driven by inflammation (a swollen joint, period cramps, dental abscess), paracetamol is fighting with one hand tied behind its back.
How Ibuprofen Works
Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID). It works by inhibiting the enzymes COX-1 and COX-2, which are responsible for producing prostaglandins — the chemical mediators of inflammation, pain and fever. By reducing prostaglandins, ibuprofen tackles pain, reduces swelling, and lowers temperature. It’s particularly effective when the pain has an inflammatory component.
Key Differences: Head to Head
| Factor | Paracetamol | Ibuprofen |
|---|---|---|
| Reduces inflammation | No | Yes |
| Reduces fever | Yes | Yes |
| Stomach safety | Safer | Can irritate stomach |
| Kidney safety | Safer | Caution with kidney disease |
| Safe in pregnancy | Preferred | Avoid in 3rd trimester |
| Safe with elderly | Generally yes | Use with caution |
| Safe with ulcers | Yes | No — avoid |
| Best for | General pain, headaches, fever | Inflammatory pain, period pain, dental pain |
When Paracetamol Is the Better Choice
Choose paracetamol when: you have a simple headache or tension headache, you have a fever (in children or adults), you have mild to moderate general pain, you’re pregnant, you have a history of stomach ulcers or gastritis, you have kidney problems, you’re elderly (ibuprofen cardiovascular and renal risks increase with age), or you’re taking blood thinners.
When Ibuprofen Is the Better Choice
Choose ibuprofen when: pain is clearly inflammatory in nature — a sprained ankle, arthritis flare, dental abscess, sinus pain, or back pain with muscle spasm. Period pain (dysmenorrhoea) — ibuprofen is the evidence-based first choice because prostaglandins drive uterine cramping. Sports injuries within 48 hours. Post-operative dental or surgical pain (short term).
Can You Take Both Together?
Yes — paracetamol and ibuprofen can safely be taken together (or alternated) because they work by entirely different mechanisms and don’t interact with each other. For moderate to severe short-term pain, alternating them every 2–3 hours can provide more consistent relief than either alone. This approach is used in clinical settings and is safe for most adults for short-term use.
Who Should NOT Take Ibuprofen?
- People with asthma where NSAIDs trigger symptoms
- Active or recent peptic ulcer disease
- Significant kidney disease
- Pregnancy (especially third trimester)
- Heart failure or ischaemic heart disease (without medical advice)
- People taking anticoagulants (warfarin, DOACs) — increased bleeding risk
- Inflammatory bowel disease
Safe Dosing Guide
Paracetamol: 500–1000mg every 4–6 hours. Maximum 4g (8 x 500mg tablets) in 24 hours for adults. Reduce to 3g maximum if small or frail.
Ibuprofen: 200–400mg every 6–8 hours with food. Maximum 1200mg per day OTC (1200mg = 3 × 400mg tablets). Higher prescription doses exist but should not be self-administered OTC.
Shop ibuprofen and paracetamol online. Related: Pain Relief 101, Period Pain Treatment.