Motrin is a brand name for ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, reduce inflammation, and lower fever. It’s one of the most widely used over-the-counter pain relievers, and it’s also available in prescription strengths for chronic inflammatory conditions.
What Motrin Treats
The FDA has approved Motrin for three primary uses: relief of mild to moderate pain, treatment of menstrual cramps, and management of rheumatoid arthritis and osteoarthritis symptoms. In practice, people reach for it for a wide range of everyday pain, including headaches, toothaches, back pain, and muscle strains.
Its anti-inflammatory properties give Motrin a particular edge for pain that involves swelling. A pulled muscle, a sprained ankle, or joint stiffness from arthritis all respond well to ibuprofen because the drug targets the underlying inflammation, not just the pain signal. This is the key difference between Motrin and acetaminophen (Tylenol), which relieves pain and reduces fever but does nothing for inflammation.
How It Works in Your Body
Your body produces compounds called prostaglandins whenever tissue is damaged or irritated. Prostaglandins trigger inflammation, swelling, and pain at the injury site, and they also play a role in raising your body temperature during illness. Motrin works by blocking the enzymes (COX-1 and COX-2) that produce these prostaglandins. With fewer prostaglandins circulating, you get less swelling, less pain, and a lower fever.
Ibuprofen binds to these enzymes rapidly and reversibly, which is part of why its effects are relatively short-lived compared to some other anti-inflammatory drugs. You can expect it to start working within about 30 minutes, with blood levels peaking at one to two hours after you take it. Its effects wear off in roughly four to six hours as your body metabolizes the drug, and it’s completely eliminated within 24 hours of your last dose.
Typical Dosing for Adults
For general pain relief, the standard adult dose is 400 milligrams every four to six hours as needed. Menstrual cramps follow the same pattern: 400 mg every four hours. For chronic conditions like osteoarthritis or rheumatoid arthritis, prescription doses range from 1,200 mg to 3,200 mg per day, split into three or four doses. Over-the-counter Motrin typically comes in 200 mg tablets, so most people take two at a time.
The over-the-counter maximum is generally 1,200 mg per day (six tablets) unless a doctor advises otherwise. Higher daily doses are available by prescription but require monitoring because the risk of side effects climbs with both dose and duration.
Motrin for Children
Children’s Motrin is available as a liquid suspension and chewable tablets, dosed by weight rather than age. If you don’t know your child’s weight, age can serve as a rough guide, but weight-based dosing is more accurate. Children can take ibuprofen every six to eight hours as needed.
One important restriction: ibuprofen should not be given to babies younger than 6 months old. It hasn’t been proven safe in that age group, and the FDA has not approved its use for infants under 6 months. For children under 6, it’s also best to avoid combination products that contain multiple active ingredients.
How Motrin Differs From Tylenol
People often treat Motrin and Tylenol as interchangeable, but they work differently and are better suited to different situations. Acetaminophen (Tylenol) reduces pain and fever but has no effect on inflammation. Ibuprofen (Motrin) does all three: pain, fever, and inflammation.
If you’re dealing with a swollen joint, a sports injury, or muscle soreness from overuse, Motrin is typically the better choice because it addresses the swelling that’s contributing to your pain. For a simple headache or fever without significant inflammation, either option works. Acetaminophen is generally easier on the stomach and is an option for people who can’t tolerate NSAIDs.
Side Effects and Risks
The most common side effects of Motrin are gastrointestinal: stomach pain, heartburn, and nausea. These happen because the same prostaglandins that cause inflammation also protect the stomach lining. When you suppress them, your stomach becomes more vulnerable. Over time or at high doses, this can progress to ulcers, bleeding, or even holes in the stomach or intestinal wall. These serious complications can develop without warning symptoms. The risk is higher in older adults, smokers, heavy drinkers, and people who use ibuprofen for extended periods.
Motrin also carries cardiovascular risks. Long-term or high-dose use is associated with an increased risk of heart attack and stroke. People with existing heart disease should be especially cautious, and anyone who has recently had a heart attack should avoid it unless specifically directed otherwise.
Your kidneys can also be affected because prostaglandins help regulate blood flow to the kidneys. Warning signs of kidney trouble include cloudy or bloody urine, back pain, or painful urination. These side effects are uncommon with occasional short-term use but become more relevant when ibuprofen is taken regularly.
Who Should Avoid Motrin
Pregnant women should not take Motrin at 20 weeks of pregnancy or later. The FDA issued a specific warning that NSAIDs used after 20 weeks can cause kidney problems in the developing baby, leading to dangerously low amniotic fluid levels. After 30 weeks, there’s an additional risk involving premature closure of a blood vessel in the baby’s heart. Low-dose aspirin (81 mg) is an exception to this rule when prescribed for pregnancy-related conditions, but other NSAIDs including ibuprofen should be avoided.
People taking blood thinners (anticoagulants) need to be cautious. Ibuprofen inhibits platelet function and can damage the stomach lining, both of which increase bleeding risk. Combining it with anticoagulants raises that risk further, particularly for gastrointestinal bleeding. If you take blood thinners for a condition like atrial fibrillation, talk to your prescriber before using Motrin even occasionally.
Others who should use caution or avoid Motrin include people with a history of stomach ulcers, those with kidney or liver disease, and anyone with aspirin-sensitive asthma, since ibuprofen can trigger similar reactions.