Naproxen Dosage: How Much to Take and When

Naproxen is available on prescription in the UK as 250 mg and 500 mg tablets, as well as a 250 mg and 500 mg gastro-resistant (enteric-coated) formulation.

The dose your doctor prescribes depends on the condition being treated and how severe your symptoms are.

Musculoskeletal and joint pain

For conditions such as osteoarthritis, rheumatoid arthritis and ankylosing spondylitis, the usual starting dose is 250 mg to 500 mg twice daily.

Most adults find that 500 mg in the morning and 500 mg in the evening provides effective relief.

The BNF states a maximum daily dose of 1,000 mg for ongoing use, although up to 1,250 mg may be used on the first day for acute flares under medical supervision.

Acute gout

Gout attacks require a higher initial loading dose. The BNF recommends 750 mg immediately, followed by 250 mg every 8 hours until the attack resolves. Treatment is usually needed for 4 to 7 days.

Period pain (dysmenorrhoea)

For menstrual cramps, the recommended dose is 500 mg initially, then 250 mg every 6 to 8 hours as needed, with a maximum of 1,250 mg on the first day and 1,000 mg daily thereafter.

Acute musculoskeletal injuries

Sprains, strains and sports injuries typically respond to 500 mg twice daily for 5 to 7 days.

Short courses minimise the risk of gastrointestinal side effects while still controlling pain and swelling effectively.

Patients over 65 are more susceptible to the adverse effects of NSAIDs, particularly gastrointestinal bleeding, renal impairment and cardiovascular events.

The BNF explicitly advises using the lowest effective dose for the shortest possible duration in this age group.

In practice, many prescribers start elderly patients on 250 mg twice daily rather than the full 500 mg twice daily dose.

This lower starting point allows assessment of efficacy and tolerability before any increase.

A proton pump inhibitor such as omeprazole 20 mg daily should be co-prescribed whenever naproxen is used for more than 7 days in an older patient.

Renal function declines naturally with age, and naproxen is primarily cleared through the kidneys. A baseline estimated glomerular filtration rate (eGFR) should be checked before starting treatment.

If the eGFR is below 30 mL/min/1.73 m2, naproxen should generally be avoided. Between 30 and 60 mL/min, the lowest dose with close monitoring of renal function is appropriate.

Blood pressure monitoring is also recommended, as NSAIDs can raise systolic pressure by 3 to 5 mmHg on average, which may be clinically significant in patients already on antihypertensive therapy.

If you are over 65 and have been prescribed naproxen, make sure you attend any follow-up appointments your doctor arranges.

Taking naproxen the right way helps you get the most benefit while keeping the risk of side effects as low as possible. These practical tips apply regardless of the dose you have been prescribed.

With food or milk

Always swallow naproxen tablets with or immediately after a meal or snack. This creates a food buffer in the stomach that reduces direct irritation of the gastric mucosa.

If you forget to eat beforehand, a glass of milk is a reasonable alternative.

Swallow whole

Gastro-resistant tablets must not be crushed, broken or chewed.

They have a special coating designed to prevent the drug from being released in the stomach, directing it instead to the small intestine where absorption is less irritating.

Spacing your doses

For twice-daily dosing, aim for roughly 12-hour intervals. For example, 8 am with breakfast and 8 pm with your evening meal.

Consistent timing maintains steady blood levels and gives more reliable pain control throughout the day and night.

Missed dose

If you miss a dose, take it as soon as you remember, provided it is not close to the time for your next dose.

Never double up to make up for a missed dose, as this increases the risk of side effects, particularly stomach irritation.

Duration of treatment

Use naproxen for the shortest time needed to control your symptoms. For acute injuries, 5 to 7 days is often sufficient.

Chronic conditions may require longer courses, but your doctor should review the need for continued treatment at regular intervals.

Naproxen is licensed for use in children aged 5 years and over for the treatment of juvenile idiopathic arthritis and certain musculoskeletal conditions.

It is not routinely used for general pain relief in children, where paracetamol and ibuprofen remain first-line choices.

The BNF for Children recommends a dose of 5 mg/kg twice daily for juvenile idiopathic arthritis, up to a maximum single dose of 500 mg. For a child weighing 30 kg, this equates to 150 mg twice daily.

Naproxen suspension (25 mg/mL) is available for children who cannot swallow tablets, though it may need to be obtained as a special order in the UK.

It is important that children taking naproxen are monitored regularly by their paediatric rheumatologist or general practitioner.

Growth, renal function and blood counts should be reviewed at least every 6 months during ongoing treatment.

Parents should watch for signs of stomach upset, unusual bruising or dark stools and report them promptly.

Naproxen should not be given to children under 2 years. Between the ages of 2 and 5, use is generally reserved for specialist-initiated treatment only.

As with adults, the tablets should be taken with food, and the lowest effective dose should always be used.

Taking more naproxen than prescribed is a situation that requires careful assessment. The severity of an overdose depends on the amount taken and whether any other substances were involved.

Mild overdose (up to 1.5 times the recommended dose)

Symptoms are usually limited to nausea, stomach pain and heartburn. In most cases, these resolve without specific treatment. Stop taking any further naproxen and drink plenty of water.

Moderate to severe overdose

Ingestion of more than 2,000 mg in a single dose can cause vomiting, drowsiness, tinnitus and occasionally seizures.

Rarely, significant overdoses have been associated with acute kidney injury and metabolic acidosis.

What to do

If you or someone else has taken substantially more than the prescribed dose, contact NHS 111 or attend A&E without delay. Bring the medication packet with you.

Treatment is supportive and may include activated charcoal if the overdose occurred within the past hour, intravenous fluids to protect kidney function and monitoring of blood chemistry.

Accidental extra dose

If you accidentally take one extra tablet (for example, 750 mg instead of 500 mg), this is unlikely to cause serious harm. Monitor for stomach discomfort and skip or delay your next dose accordingly.

If you are unsure, phone your pharmacist or NHS 111 for personalised advice.

Keep naproxen out of reach of children and store it in its original packaging to avoid confusion with other medicines.

Several commonly used medicines interact with naproxen in ways that may require a dose change or closer monitoring.

Always inform your prescriber and pharmacist of everything you take, including herbal products.

Anticoagulants (warfarin, apixaban, rivaroxaban)

Naproxen increases the risk of bleeding when combined with blood thinners.

If concurrent use is unavoidable, the lowest naproxen dose should be used alongside gastroprotection, and INR or bleeding symptoms should be monitored closely.

Antihypertensives (ACE inhibitors, ARBs, diuretics)

NSAIDs can blunt the blood-pressure-lowering effect of these drugs and increase the risk of acute kidney injury, particularly the so-called triple whammy combination of ACE inhibitor plus diuretic plus NSAID.

Blood pressure and renal function should be checked within 1 to 2 weeks of starting naproxen in these patients.

SSRIs (fluoxetine, sertraline, citalopram)

Selective serotonin reuptake inhibitors independently increase bleeding risk. Combining an SSRI with naproxen approximately doubles the risk of upper GI bleeding compared with either drug alone.

A PPI is strongly recommended if both are needed.

Lithium and methotrexate

Naproxen can raise plasma levels of lithium and methotrexate by reducing their renal clearance. Levels should be monitored when starting or stopping naproxen in patients on either of these drugs.

Other NSAIDs

Never combine naproxen with another oral NSAID, including over-the-counter ibuprofen. Doing so increases the risk of GI bleeding and kidney injury without providing additional pain relief.