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How long does it take for ibuprofen to work?

In this article you will find out everything you need to know about how long it takes for ibuprofen to work and other alternative ways to help pain.

There are numerous FDA-approved pain killers available under different brand names. These include Paracetamol, Naproxen, Diclofenac and Ibuprofen. The two common brands under which Ibuprofen is sold include Advil and Motrin. Ibuprofen, a Non-steroid anti-inflammatory drug (NSAID), is mainly prescribed as an over-the-counter pain reliever and anti-inflammatory agent. Even though it was initially discovered as a therapy for rheumatoid arthritis, it is now recommended for pain like period pain, back pain, toothache, migraine, muscle sprains, joint pains, and even a sore throat.

It is found effective for mild to moderate pain. The over-the-counter forms of Ibuprofen are often designed for mild pains. The effect of Ibuprofen on severe types of pain, as seen after an operation, has been investigated in several clinical trials. The results of such studies show that patients who were given IV ibuprofen had lower pain scores than those given other pain relievers like Acetaminophen. (1)

How Does It Work?

NSAIDs like ibuprofen work by inhibiting the release of prostaglandin and its precursors. Whenever the body undergoes a pathological stimulus, chemicals like arachidonic acid are produced by an enzyme known as Phospholipase A2. This arachidonic acid then undergoes certain enzymatic pathways. These include cyclooxygenase, lipoxygenase, or cytochrome P450 pathway.

The cyclooxygenase pathways work by forming prostaglandins from arachidonic acid, while the lipoxygenase pathway causes the formation of hydroxy eicosatetraenoic acids and leukotriene. The Cytochrome P450 pathway converts arachidonic acid to eicosatetraenoic hydroxy acids and epoxyeicosatrienoic acids. (2) The release of these chemicals by conversion of arachidonic acid brings about several changes in the body. These include increased vascular permeability, muscle tone, platelet aggregation, and replication of cells. They are also involved in promoting inflammation, atopy, angiogenesis, and cancer. (3)

When an individual takes Ibuprofen, the drug inhibits the COX 1 and COX 2 pathways in the body, which in turn causes reduced production of prostaglandins. The reduced prostaglandins then further reduce the pathological changes in the body. This is what gives NSAIDs like Ibuprofen their analgesic, anti-inflammatory, and anti-pyretic properties. (4) While the effect of different NSAIDs is not identical, Ibuprofen has a much greater affinity for the Cox 1 pathways than inhibition of cox two pathways.

How Can Ibuprofen Be Administered?

Over-the-counter use of Ibuprofen has become common in many countries around the world. This may be available in the form of intravenous solutions, topics ointments and gels, oral supplements, chewable tablets, sprays, and even a combination of the above. Healthcare professionals often recommend that oral tablets of Ibuprofen be taken with food. However, the intravenous route is not commonly recommended and should only be opted in a healthcare setup after medical advice. (5) The IV formulation for Ibuprofen are a mixture of Lysine and ibuprofen. Moreover, they are administered over 30 minutes to the adults and 10 minutes to the children.

How long does it take for ibuprofen to work?

According to the NHS, otc ibuprofen takes at least 20 to 30 minutes to show its effects. When Ibuprofen is taken orally, it may reach its maximum concentration in the blood between one to two hours. So if even the individual may start feeling some relief after 30 minutes, they may experience the maximum effects between 1 to 2 hours, when their plasma concentration is the highest. However, this may vary between different formulations of oral supplements. The pharmacokinetics for these drugs normally show linear patterns as well. (6)

At doses recommended by the doctor, the drug gets firmly bound to the plasma proteins, so it is able to show its effect for longer. (7)  Individuals who are taking other drugs like Phenytoin and Warfarin should be careful while starting Ibuprofen since there may be chances of drug-drug interaction – even if they are low. In addition, while the pain relief effects of Ibuprofen are experienced much earlier, it may take a slightly longer time for the anti-inflammatory effects to become apparent. They may vary from a few days to as much as a few weeks.

The plasma half-life of Ibuprofen is also found to be between one to three hours, which means repeated intake may be required. (7) Moreover, it is also observed that the effects of Ibuprofen last much longer in adults as compared to children, who have a much faster metabolism.

Common Side Effects of Ibuprofen

Even though Ibuprofen is considered a safe drug, when taken according to the recommended dose and frequency, there are certain individuals who should be extra careful while using it. These include individuals with cardiovascular problems, kidney diseases, high blood pressure, a recent history of heart attack or prolonged heart diseases, expecting mothers, or those who are breastfeeding. In elderly individuals, the renal functions should be constantly monitored, especially when they are on high-dose Ibuprofen or taking diuretics. The assessment of blood pressure should also accompany this. Children who are at high risk for liver diseases and are being given Ibuprofen should also be kept under close observation, as the use of Acetaminophen and Ibuprofen may lead to NSAID-induced liver injury. This is even more serious because there is usually no cure for the liver injury caused by NSAID use. This is why adults are often advised to only give medications to children after medical advice. (8)

The adverse effects which may be associated with ibuprofen tablets include bloating, stomach pain, heartburn, stomach ulcers, indigestion, constipation, and stomach upset. This is why it is recommended to always start with a low dose of Ibuprofen in order to lower the risk of adverse effects. These individuals should first be evaluated for any adverse symptoms before taking the next dose. Some individuals may also experience allergic reactions, which may present as rashes or shortness of breath. (9)

How Long Do The Effects of Ibuprofen Last?

The effects of Ibuprofen may last between 4 to 6 hours; however, it may take at least 24 hours for Ibuprofen itself to leave the body. The half-life of Ibuprofen is usually 2 hours, so every two hours that pass since the intake of an ibuprofen tablet, its levels inside the body fall by half. This continues until it is completely removed. (10)

Frequentley asked Questions:

  1. How does ibuprofen know what hurts?
  2. Is it OK to take 2 ibuprofen every night?
  3. What happens if u take ibuprofen on an empty stomach?
  4. Does ibuprofen make you sleepy?
  5. What should I avoid while taking ibuprofen?
  6. When is ibuprofen at its peak?


  1.   Ekinci, M., Ciftci, B., Celik, E. C., Köse, E. A., Karakaya, M. A., & Ozdenkaya, Y. (2020). A Randomized, Placebo-Controlled, Double-Blind Study that Evaluates Efficacy of Intravenous Ibuprofen and Acetaminophen for Postoperative Pain Treatment Following Laparoscopic Cholecystectomy Surgery. Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract, 24(4), 780–785. https://doi.org/10.1007/s11605-019-04220-1
  2.   Hiľovská, L., Jendželovský, R., & Fedoročko, P. (2015). Potency of non-steroidal anti-inflammatory drugs in chemotherapy. Molecular and clinical oncology, 3(1), 3–12. https://doi.org/10.3892/mco.2014.446
  3.   Harizi, H., Corcuff, J. B., & Gualde, N. (2008). Arachidonic-acid-derived eicosanoids: roles in biology and immunopathology. Trends in molecular medicine, 14(10), 461–469. https://doi.org/10.1016/j.molmed.2008.08.005
  4.   Schwier, N., & Tran, N. (2016). Non-Steroidal Anti-Inflammatory Drugs and Aspirin Therapy for the Treatment of Acute and Recurrent Idiopathic Pericarditis. Pharmaceuticals (Basel, Switzerland), 9(2), 17. https://doi.org/10.3390/ph9020017
  5.   Ferguson J. M. (2019). Pharmacotherapy for patent ductus arteriosus closure. Congenital heart disease, 14(1), 52–56. https://doi.org/10.1111/chd.12715
  6.   Evans, A. M., Nation, R. L., Sansom, L. N., Bochner, F., & Somogyi, A. A. (1990). The relationship between the pharmacokinetics of ibuprofen enantiomers and the dose of racemic Ibuprofen in humans. Biopharmaceutics & drug disposition, 11(6), 507–518. https://doi.org/10.1002/bdd.2510110605
  7.   Davies N. M. (1998). Clinical pharmacokinetics of ibuprofen. The first 30 years. Clinical pharmacokinetics, 34(2), 101–154. https://doi.org/10.2165/00003088-199834020-00002
  8.   Norman, H., Elfineh, M., Beijer, E., Casswall, T., & Németh, A. (2014). Även ibuprofen, inte bara paracetamol, kan ge barn allvarlig leverskada. NSAID bör användas med försiktighet hos barn, visar fall med letal utgäng [Also ibuprofen, not just paracetamol, can cause serious liver damage in children. NSAIDs should be used with caution in children, as shown in case with fatal outcome]. Lakartidningen, 111(40), 1709–1711.
  9.   Aljadhey, H., Tu, W., Hansen, R. A., Blalock, S. J., Brater, D. C., & Murray, M. D. (2012). Comparative effects of non-steroidal anti-inflammatory drugs (NSAIDs) on blood pressure in patients with hypertension. BMC cardiovascular disorders, 12, 93. https://doi.org/10.1186/1471-2261-12-93
  10.   Mazaleuskaya, L. L., Theken, K. N., Gong, L., Thorn, C. F., FitzGerald, G. A., Altman, R. B., & Klein, T. E. (2015). PharmGKB summary: ibuprofen pathways. Pharmacogenetics and genomics, 25(2), 96–106. https://doi.org/10.1097/FPC.0000000000000113

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