Ibuprofen vs naproxen: how two common anti-inflammatories differ

Ibuprofen and naproxen are both NSAIDs used for pain from muscle and joint problems, headaches, period pain, dental pain and fever, and for inflammatory conditions such as arthritis under medical supervision. They reduce production of prostaglandins, chemicals involved in pain and inflammation. The same mechanism that gives benefit also explains their side effects: prostaglandins protect the stomach lining and help maintain kidney blood flow.

Because of this shared action, the main risks are the same for both: indigestion, stomach ulcers and bleeding, fluid retention, effects on kidney function, raised blood pressure, and a small increase in the risk of heart attack and stroke, mainly with higher doses and longer use. The risk of problems increases in older people, those with other illnesses, and when combined with certain medicines.

The clearest difference is duration. Ibuprofen has a relatively short effect, so the leaflet directs several doses spread across the day, while naproxen lasts longer, so doses are less frequent. For some people the convenience of fewer doses matters, and for others the shorter action of ibuprofen offers more flexibility.

Differences in safety are small and debated. Some evidence suggests naproxen may carry a lower cardiovascular risk than some other NSAIDs, while stomach irritation risk is generally considered to be somewhat lower with ibuprofen at low doses, but these differences depend on dose, duration and the person, and neither is risk free. Supply also differs: ibuprofen is available more widely, while naproxen is usually obtained under pharmacist supervision or on prescription.

NSAIDs are not suitable for everyone. Anyone with a history of stomach ulcer or gastrointestinal bleeding, kidney disease, heart failure, uncontrolled high blood pressure or a previous reaction to aspirin or NSAIDs should avoid them or seek advice. People with asthma should check, since some are sensitive to NSAIDs. Those taking anticoagulants such as warfarin, antiplatelet medicines, certain blood pressure tablets, diuretics, lithium or methotrexate need advice because of interactions.

Pregnancy and breastfeeding need specific advice, and NSAIDs are generally avoided in the later stages of pregnancy. Older adults are more vulnerable to side effects, and a pharmacist or doctor can suggest alternatives, such as paracetamol or topical treatments, where appropriate.

The MHRA and NHS guidance emphasise using the lowest effective dose for the shortest time, taking tablets with or after food, and not combining two NSAIDs, including those bought without prescription, such as an NSAID gel plus tablets without advice, or aspirin taken for pain alongside ibuprofen. Anyone needing an NSAID regularly should have a medicine review, and some may be advised a stomach-protecting medicine.

The choice between ibuprofen and naproxen is generally made on practicality and individual risk rather than on a large difference in effect. A prescriber may choose one over the other based on heart risk, stomach risk, the condition treated and how often dosing is convenient.

• Short-lived pain such as a headache or sprain: either may be used according to the leaflet, subject to cautions.

• Pain lasting beyond a few days: speak to a pharmacist or GP rather than continuing to self-treat.

• Existing stomach, kidney, heart or blood pressure problems, or taking anticoagulants: ask before taking either.

• Pregnant or breastfeeding: ask a pharmacist, midwife or doctor first.

• Taking other pain relievers: check that products do not contain overlapping ingredients.

• Black stools, vomiting blood, severe stomach pain, swelling or breathlessness after taking an NSAID: seek urgent medical help.

Neither is "gentler" in every person, and neither is risk free just because it is sold over the counter. Taking an NSAID on an empty stomach increases irritation. Doubling up on different brand names of the same medicine is a common mistake. And NSAIDs do not treat the cause of most chronic pain; they ease symptoms.

Another misconception is that naproxen is a stronger version of ibuprofen. Both can be effective at appropriate doses, and the better choice is individual.