Motrin outsells most rival ibuprofen brands in American pharmacies, but plenty of shoppers don’t realize Motrin is ibuprofen and that acetaminophen is a completely different drug. The Motrin vs acetaminophen question is really “NSAID vs central analgesic,” and the answer depends on whether your pain involves inflammation, what medications you take, and how your kidneys, liver, and stomach are doing. For a broader overview of OTC pain care, visit our medical conditions guide. Short version: Motrin for inflammation-driven pain, acetaminophen for fever and simple pain when NSAIDs are risky.
Quick Comparison
Motrin is a brand name for ibuprofen, a nonsteroidal anti-inflammatory drug sold by Johnson & Johnson. Acetaminophen is the generic name for the drug sold as Tylenol in the United States and paracetamol internationally. Motrin comes in 200 mg OTC tablets and 400/600/800 mg prescription strengths; acetaminophen comes in 325 mg, 500 mg, and 650 mg extended-release forms.
How They Work Differently
Motrin (ibuprofen) inhibits both COX-1 and COX-2 enzymes, blocking prostaglandin synthesis throughout the body. That reduces inflammation, pain, and fever simultaneously. According to the NIH StatPearls entry on ibuprofen, the drug reaches peak plasma concentration in 1 to 2 hours and has a half-life of about 2 hours.
Acetaminophen works mostly in the central nervous system. It raises pain thresholds and affects the hypothalamic temperature-regulating center, which makes it effective against pain and fever without touching peripheral inflammation. That is why acetaminophen is a lousy choice for a swollen ankle but a fine choice for a tension headache.
Effectiveness Research
For inflammatory conditions (dental pain, gout, musculoskeletal injury, dysmenorrhea), randomized trials consistently favor ibuprofen. A 2013 Cochrane review on acute postoperative pain found ibuprofen 400 mg gave more patients 50 percent or better pain relief than acetaminophen 1000 mg.
For fever and non-inflammatory headaches, the two work about the same. Pediatric fever trials show both drugs reduce temperature by comparable amounts, though ibuprofen has slightly longer duration of action per dose.
Side Effects Compared
Motrin’s most common side effects are heartburn, nausea, and dyspepsia. Serious risks include gastric ulcers, GI bleeding (roughly 1 to 2 percent per year of chronic use), kidney injury (especially with dehydration), modest blood pressure increases, fluid retention, and cardiovascular events with long-term use. The FDA added a boxed warning in 2015 about heart attack and stroke risk for all non-aspirin NSAIDs.
Acetaminophen has a cleaner everyday side effect profile. It does not cause ulcers, does not raise blood pressure, and does not meaningfully impair kidney function. Its one serious risk is hepatotoxicity in overdose or in people who drink heavily. The FDA caps single-ingredient acetaminophen at 325 mg per tablet in combination products and recommends keeping total daily intake under 4,000 mg for most adults.
Dosing and How to Take Them
Adult Motrin dosing is 200 to 400 mg every 4 to 6 hours with a 1,200 mg OTC daily cap. Take with food or milk to reduce stomach irritation. Pediatric dosing is 10 mg/kg every 6 to 8 hours for kids over 6 months.
Adult acetaminophen dosing is 325 to 1,000 mg every 4 to 6 hours, with total daily intake ideally under 3,000 mg and absolute max 4,000 mg. Food does not affect absorption. Watch hidden acetaminophen in cold medicines, sleep aids, and prescription combos like Norco.
Which Is Better for Common Conditions
Menstrual cramps, dental pain, minor sprains, tendinitis, gout, and arthritis flares: Motrin is the better pick because inflammation is the dominant driver. Tension headaches, fever alone, post-vaccine soreness, and pain in pregnancy or in patients with active GI or kidney disease: acetaminophen is better. For migraine, both can help, though some clinicians prefer an NSAID plus caffeine combination.
In children with fever, either is acceptable per AAP guidance. Avoid Motrin in infants under 6 months.
Cost and Availability
Both are OTC and cheap. Generic ibuprofen 200 mg runs $5 to $10 for 100 tablets; brand Motrin is roughly double. Generic acetaminophen runs $5 to $10 for 100 tablets; brand Tylenol is similarly priced at a premium. No prescription is needed for standard strengths.
Interactions and Warnings
Motrin interacts with ACE inhibitors, ARBs, diuretics (triple-whammy kidney risk), lithium, methotrexate, SSRIs, warfarin, and all anticoagulants. It should be avoided in the third trimester of pregnancy, in patients with active peptic ulcers, severe CKD, or recent coronary bypass.
Acetaminophen interacts meaningfully with warfarin (sustained use raises INR) and should be avoided or tightly capped in patients with significant liver disease or heavy alcohol use. Both drugs should be discussed with a pharmacist if you take multiple medications. For related reading, see our Tylenol vs ibuprofen comparison and ibuprofen vs Motrin guide.
Frequently Asked Questions
Is Motrin stronger than acetaminophen?
For inflammatory pain, yes, at equivalent OTC doses. For simple pain and fever without inflammation, they perform similarly. “Stronger” depends on the source of the pain more than on the drug.
Can I take Motrin and acetaminophen together?
Yes. They work by different mechanisms and can be combined or alternated. Stay within each drug’s daily maximum and space doses intentionally.
Which is safer for the stomach?
Acetaminophen, by a wide margin. It does not irritate the stomach lining or cause ulcers. Motrin and all NSAIDs do.
Can I drink alcohol with either drug?
Light drinking is generally fine with either at therapeutic doses. Heavy drinkers should be cautious with both: Motrin raises GI bleed risk and acetaminophen raises hepatotoxicity risk. The FDA recommends keeping daily alcohol under three drinks if you use these drugs regularly.
The Bottom Line
Motrin vs acetaminophen comes down to what is causing the pain and what else your body is dealing with. Motrin gives more pain relief for inflammatory conditions but carries real risks for stomach, kidneys, and blood pressure. Acetaminophen is gentler on most body systems and is the preferred choice during pregnancy, in kidney disease, on blood thinners, or alongside heavy medication lists. Neither is “better” across the board; matching drug to situation beats brand loyalty every time.