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How long does ibuprofen take to work?

Medically reviewed by Carmen Pope, BPharm. Last updated on July 18, 2025.

Official Answer by Drugs.com

Ibuprofen starts working within 20 to 30 minutes after taking it, with maximum pain relief effects occurring within 1 to 2 hours. For people with chronic pain lasting weeks or months, it may take several days of regular ibuprofen dosing before noticeable pain relief occurs.

Taking ibuprofen on an empty stomach may give you faster symptom relief, although it may increase the risk of stomach-related side effects, such as indigestion or heartburn. Food slows ibuprofen absorption time but doesn't affect the total amount absorbed by your body.

One dose of ibuprofen provides effective pain relief for four to six hours. But it may take at least 10 hours for your body to completely eliminate ibuprofen from your system. This is because ibuprofen has a half life of 1.9 to 2.2 hours and experts generally agree it takes 4 to 5 half lives for your body to completely eliminate ibuprofen, which equals approximately 10 hours.

This means while pain relief wears off after 4-6 hours, traces of ibuprofen remain in your bloodstream for up to 10 hours, which is important for avoiding overdose when taking multiple doses.

References

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Naproxen vs ibuprofen: What's the difference?

Ibuprofen is short acting, while naproxen is long acting and more likely to cause an upset stomach. Naproxen also increases the risk of uncontrolled bleeding in people taking blood thinners by 4-fold, and ibuprofen increases the risk 2-fold. Naproxen and ibuprofen are both NSAIDs so they are similar in many ways, but there are important differences. Continue reading

Can you take ibuprofen on an empty stomach?

Despite the common belief that you must take ibuprofen with food, you can safely take low-dose ibuprofen (up to 1200 mg daily in divided doses for 1 to 7 days) on an empty stomach, and this provides faster pain relief than taking ibuprofen with food. Food slows ibuprofen absorption time, although it doesn't affect the total amount absorbed. There is actually no scientific evidence that taking ibuprofen with food prevents stomach irritation. Over-the-counter ibuprofen doses have a low incidence of gastric problems anyway.

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Can you take expired ibuprofen?

Although taking expired ibuprofen is not recommended by the manufacturer, the actual shelf-life is likely to be longer than that indicated by the expiry date, with FDA testing showing many drugs are active for years beyond their expiry date, although specific data on ibuprofen is not available. Within reason, an ibuprofen tablet that is a few months past its expiry date is probably safe to take. Ibuprofen that is years past its expiry date should not be taken. Continue reading

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